feat(渲染能力): 完善三维渲染、字体及版本保存

go.mod

@@ -7,9 +7,9 @@ require (
 	github.com/emmansun/gmsm v0.45.0
 	github.com/go-text/typesetting v0.3.5
 	github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c
-	github.com/xiaoqidun/j2kgo v0.0.0-20261009063910-4865a21ef893
+	github.com/xiaoqidun/j2kgo v0.0.0-20261011021706-cedb3037ff6e
 	github.com/xiaoqidun/jbig2 v1.1.4
-	github.com/xiaoqidun/pdfgo v0.0.0-20261010065159-b32618b0bdd7
+	github.com/xiaoqidun/pdfgo v0.0.0-20261011021850-35fe3f96d36f
 	golang.org/x/crypto v0.58.0
 	golang.org/x/image v0.47.0
 	golang.org/x/text v0.43.0

go.sum

@@ -58,12 +58,12 @@ github.com/tdewolff/parse/v2 v2.8.16 h1:bLk5svUOQRkW/Y2SJ+DeENSIkZBcTIkq+Atyv5D8
 github.com/tdewolff/parse/v2 v2.8.16/go.mod h1:XdsoSFThlVIRIajAuqz1evNY7bagZS8LBOPA3aVopwQ=
 github.com/tdewolff/test v1.0.12 h1:7F21DqIajswxuche0geHdrUZRCWE4oko4b7bcmkkrxk=
 github.com/tdewolff/test v1.0.12/go.mod h1:XPuWBzvdUzhCuxWO1ojpXsyzsA5bFoS3tO/Q3kFuTG8=
-github.com/xiaoqidun/j2kgo v0.0.0-20261009063910-4865a21ef893 h1:jmQlBO7R+bcimOMs9jjyDWR1FqiPNGtZqA/V1WiYfPA=
+github.com/xiaoqidun/j2kgo v0.0.0-20261011021706-cedb3037ff6e h1:OuRcvG5g5AieBN3fNKo130Iu3f+6/ihiWSe8//QT1qg=
-github.com/xiaoqidun/j2kgo v0.0.0-20261009063910-4865a21ef893/go.mod h1:DCwAfuDzCDYqUiAlZ7BDwigTjaXw7o9L1FtEma/D1aA=
+github.com/xiaoqidun/j2kgo v0.0.0-20261011021706-cedb3037ff6e/go.mod h1:DCwAfuDzCDYqUiAlZ7BDwigTjaXw7o9L1FtEma/D1aA=
 github.com/xiaoqidun/jbig2 v1.1.4 h1:LF6J1si4JY+TszTh9+m4KAg9/ba0JjfXoGtQTQC2S8c=
 github.com/xiaoqidun/jbig2 v1.1.4/go.mod h1:9jromqVwMqlptUDEt6Yip8vqYA5I1YjhG7FgMl/Z2dA=
-github.com/xiaoqidun/pdfgo v0.0.0-20261010065159-b32618b0bdd7 h1:VFrEkWzhLLgoMZ4FNH/uN/Mdfo/TSGKzIPjqCL4m3J4=
+github.com/xiaoqidun/pdfgo v0.0.0-20261011021850-35fe3f96d36f h1:m3yM1CzrHWm+LW84WWcA2Kr1Ux8K/Znrgd0XVxGEtIw=
-github.com/xiaoqidun/pdfgo v0.0.0-20261010065159-b32618b0bdd7/go.mod h1:fXz1emtF1YCpcIv+fglDZstjkHxjS2l3G4DVMgUzVnk=
+github.com/xiaoqidun/pdfgo v0.0.0-20261011021850-35fe3f96d36f/go.mod h1:hkZn8gHOI94K0fE2ynbXaE8J5T0/jCvoTS/yroKgb+E=
 github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
 github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
 github.com/yuin/goldmark v1.8.5 h1:r6N5afV5qj/5S4UTch8agZHJ8UxNCMwX7WjkkJam2NA=

ofdgo_editor_font.go

@@ -151,6 +151,30 @@ func (u *editorFontUsage) merge(other *editorFontUsage, unsafe bool) {
 	}
 }
 
+// editorObjectFontScan 判断对象是否需要扫描嵌套文字或复合资源
+// 入参: object 图形对象
+// 返回: bool 是否需要完整引用扫描
+func editorObjectFontScan(object GraphicObject) bool {
+	var clips *Clips
+	var fill, stroke *FillColor
+	switch object.Type {
+	case "CompositeObject", "CompositeGraphicUnit":
+		return true
+	case "TextObject", "Text":
+		clips = object.TextObject.Clips
+		fill, stroke = object.TextObject.FillColor, (*FillColor)(object.TextObject.StrokeColor)
+	case "PathObject", "Path":
+		clips = object.PathObject.Clips
+		fill, stroke = object.PathObject.FillColor, (*FillColor)(object.PathObject.StrokeColor)
+	case "ImageObject":
+		clips = object.ImageObject.Clips
+		if object.ImageObject.Border != nil {
+			stroke = (*FillColor)(object.ImageObject.Border.BorderColor)
+		}
+	}
+	return clips != nil || fill != nil && fill.Pattern != nil || stroke != nil && stroke.Pattern != nil
+}
+
 // subsetFonts 收集新增字体实际使用的字形，仅裁剪保存结果，保留完整编辑字体
 // 入参: progress 保存进度回调
 // 返回: map[string][]byte 包内字体子集, error 错误信息
@@ -181,11 +205,17 @@ func (e *Editor) subsetFonts(progress editorProgress) (map[string][]byte, error)
 		return nil, progress.report("fonts", 0, 0)
 	}
 	refs := editorResourceRefs{ids: make(map[string]bool), files: make(map[string]bool)}
-	composite := false
+	nested := false
+	for _, resource := range e.resources {
+		if resource.draw != nil {
+			nested = true
+			break
+		}
+	}
 	if e.source != nil {
 		for _, name := range e.annotationFiles() {
 			if data, changed := e.source.reader.files[name]; changed {
-				composite = true
+				nested = true
 				if _, safe := refs.scan(bytes.NewReader(data), name); !safe {
 					return nil, nil
 				}
@@ -199,8 +229,8 @@ func (e *Editor) subsetFonts(progress editorProgress) (map[string][]byte, error)
 		}
 		for _, layer := range page.Content.Layer {
 			for _, object := range layer.Objects {
-				if object.Type == "CompositeObject" || object.Type == "CompositeGraphicUnit" {
+				if editorObjectFontScan(object) {
-					composite = true
+					nested = true
 					origin := e.objectOrigin(editorObjectID(object))
 					var data []byte
 					var err error
@@ -218,6 +248,7 @@ func (e *Editor) subsetFonts(progress editorProgress) (map[string][]byte, error)
 					if _, safe := refs.scan(bytes.NewReader(data), "Page.xml"); !safe {
 						return nil, nil
 					}
+					continue
 				}
 				if object.Type != "TextObject" {
 					continue
@@ -246,10 +277,10 @@ func (e *Editor) subsetFonts(progress editorProgress) (map[string][]byte, error)
 			}
 		}
 	}
-	if composite {
+	if nested {
 		_, _, _, files := e.usedResources()
 		for i, resource := range e.resources {
-			if resource.composite == "" || !slices.Contains(files, resource.name) {
+			if resource.definition() == "" || !slices.Contains(files, resource.name) {
 				continue
 			}
 			if err := progress.report("fonts", len(e.pages)+i, total); err != nil {

ofdgo_editor_xml.go

@@ -16,6 +16,7 @@ package ofdgo
 
 import (
 	"bytes"
+	"context"
 	"encoding/xml"
 	"fmt"
 	"io"
@@ -42,10 +43,26 @@ type editorXMLPatch struct {
 // 入参: data XML原文
 // 返回: *editorXML 根节点, error 错误信息
 func parseEditorXML(data []byte) (*editorXML, error) {
-	d := xml.NewDecoder(bytes.NewReader(data))
+	return parseEditorXMLContext(nil, data)
+}
+
+// parseEditorXMLContext 解析XML节点位置并响应取消
+// 入参: ctx 取消上下文，可为nil, data XML原文
+// 返回: *editorXML 根节点, error 解析或取消错误
+func parseEditorXMLContext(ctx context.Context, data []byte) (*editorXML, error) {
+	var input io.Reader = bytes.NewReader(data)
+	if ctx != nil {
+		input = imageInput{ReadCloser: io.NopCloser(input), context: ctx}
+	}
+	d := xml.NewDecoder(input)
 	var root *editorXML
 	var stack []*editorXML
 	for {
+		if ctx != nil {
+			if err := ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
 		start := int(d.InputOffset())
 		token, err := d.Token()
 		if err == io.EOF {
@@ -131,7 +148,12 @@ func editorPatchXML(data []byte, patches []editorXMLPatch) []byte {
 		}
 		return a.end - b.end
 	})
+	size := len(data)
+	for _, patch := range patches {
+		size += len(patch.data) - (patch.end - patch.start)
+	}
 	var result bytes.Buffer
+	result.Grow(size)
 	position := 0
 	for _, patch := range patches {
 		result.Write(data[position:patch.start])

ofdgo_font_backend.go

@@ -86,8 +86,17 @@ type FontShaperOptions interface {
 	ShapeTextWithOptions(value string, size float64, options TextShapeOptions) ([]ShapedGlyph, error)
 }
 
+// FontShaperRun 保留完整单行原文的上下文，仅塑形指定区间，不执行字体回退
+// start和end为原文的符文索引，区间左闭右开，返回Cluster仍使用原文索引
+// 调用方负责方向和脚本分段，options.Bidi须为false；坐标相对当前区间的基线起点
+// value为已校验的原文符文序列，调用期间不得修改，返回结果不引用该切片
+type FontShaperRun interface {
+	FontShaperOptions
+	ShapeTextRun(value []rune, start, end int, size float64, options TextShapeOptions) ([]ShapedGlyph, error)
+}
+
 // ShapedGlyph 保存塑形后的字形、原文簇和基线定位
-// Bidi模式下VisualOrder为簇从左到右的零起始顺序，同簇字形共用顺序
+// VisualOrder为簇从左到右的零起始顺序，同簇字形共用顺序
 type ShapedGlyph struct {
 	Glyph         uint16
 	Cluster       int

ofdgo_font_cff2.go

@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
-	"maps"
 	"math"
 
 	"github.com/go-text/typesetting/font/cff"
@@ -172,10 +171,11 @@ func staticCIDFont(table map[string][]byte, chars [][]byte) ([]byte, error) {
 	}
 	names := encodeCFFIndex([][]byte{[]byte(name)})
 	strings := encodeCFFIndex([][]byte{[]byte("Adobe"), []byte("Identity")})
-	charset := []byte{0}
+	cids := make([]int, len(chars))
 	for gid := 1; gid < len(chars); gid++ {
-		charset = binary.BigEndian.AppendUint16(charset, uint16(gid))
+		cids[gid] = gid
 	}
+	charset := encodeCFFSubsetCharset(cids)
 	selects := []byte{3, 0, 1, 0, 0, 0}
 	selects = binary.BigEndian.AppendUint16(selects, uint16(len(chars)))
 	fonts := encodeCFFIndex([][]byte{encodeCFFDict(cffDict{18: {0, 0}})})
@@ -203,109 +203,3 @@ func staticCIDFont(table map[string][]byte, chars [][]byte) ([]byte, error) {
 	}
 	return nil, fmt.Errorf("CFF offsets did not converge")
 }
-
-// staticCFFPrograms 读取无子程序和私有字典的CID字形，其他CFF保留原有保存策略
-// 入参: sfnt 已解析字体
-// 返回: [][]byte 独立字形程序，不符合条件时为空
-func staticCFFPrograms(sfnt *sfntFont) [][]byte {
-	data := sfnt.Tables["CFF "]
-	if len(data) < 4 {
-		return nil
-	}
-	_, end, err := readType2Index(data, int(data[2]))
-	if err != nil {
-		return nil
-	}
-	tops, end, err := readType2Index(data, end)
-	if err != nil || len(tops) != 1 {
-		return nil
-	}
-	_, end, err = readType2Index(data, end)
-	if err != nil {
-		return nil
-	}
-	globals, _, err := readType2Index(data, end)
-	if err != nil || len(globals) != 0 {
-		return nil
-	}
-	dict, err := readCFFDict(tops[0])
-	if err != nil || len(dict[1230]) != 3 {
-		return nil
-	}
-	matrix, err := readCFFMatrix(dict, [6]float64{.001, 0, 0, .001, 0, 0})
-	if err != nil || matrix[0] != matrix[3] || matrix[1] != 0 || matrix[2] != 0 || matrix[4] != 0 || matrix[5] != 0 || math.Abs(matrix[0]*float64(sfnt.UnitsPerEm())-1) > 1e-6 {
-		return nil
-	}
-	offset, err := cffDictOffset(data, dict, 1236)
-	if err != nil {
-		return nil
-	}
-	fds, _, err := readType2Index(data, offset)
-	if err != nil || len(fds) != 1 {
-		return nil
-	}
-	fd, err := readCFFDict(fds[0])
-	if err != nil || len(fd) != 1 || len(fd[18]) != 2 || fd[18][0] != 0 {
-		return nil
-	}
-	offset, err = cffDictOffset(data, dict, 17)
-	if err != nil {
-		return nil
-	}
-	chars, _, err := readType2Index(data, offset)
-	if err != nil || len(chars) != int(sfnt.NumGlyphs()) {
-		return nil
-	}
-	return chars
-}
-
-// subsetStaticCFFFont 裁剪静态CID字形并保留原编号、字符映射和度量
-// 入参: sfnt 已解析字体, glyphs 使用的字形
-// 返回: []byte 字体子集, error 裁剪错误
-func subsetStaticCFFFont(sfnt *sfntFont, glyphs []uint16) ([]byte, error) {
-	chars := staticCFFPrograms(sfnt)
-	if chars == nil {
-		return nil, fmt.Errorf("CFF font cannot be subset safely")
-	}
-	keep := make(map[uint16]bool, len(glyphs)+1)
-	keep[0] = true
-	for _, gid := range glyphs {
-		if int(gid) >= len(chars) {
-			return nil, fmt.Errorf("CFF glyph index out of range")
-		}
-		keep[gid] = true
-	}
-	empty := make(map[uint16][]byte)
-	for gid := range chars {
-		if !keep[uint16(gid)] {
-			width := sfnt.GlyphAdvance(uint16(gid))
-			program := empty[width]
-			if program == nil {
-				var err error
-				program, err = cffOutlineProgram(nil, width)
-				if err != nil {
-					return nil, err
-				}
-				empty[width] = program
-			}
-			chars[gid] = program
-		}
-	}
-	table := maps.Clone(sfnt.Tables)
-	var err error
-	table["CFF "], err = staticCIDFont(table, chars)
-	if err != nil {
-		return nil, err
-	}
-	mapping := make(map[rune]uint16)
-	for gid := range keep {
-		for _, char := range sfnt.glyphCharacters(gid) {
-			mapping[char] = gid
-		}
-	}
-	table["cmap"] = buildCmapTable(sfnt.NumGlyphs(), mapping)
-	for _, tag := range []string{"DSIG", "GSUB", "GPOS", "GDEF"} {
-		delete(table, tag)
-	}
-	return serializeOTF(table)
-}

ofdgo_font_cff_cid_subset.go

@@ -0,0 +1,239 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+)
+
+// cidSubsetFont 保存CID字体裁剪所需的字典、映射和执行资源
+type cidSubsetFont struct {
+	prefix  []byte
+	strings [][]byte
+	top     cffDict
+	dicts   []cffDict
+	private []cffDict
+	fonts   []*type2Font
+	selects []int
+	charset []byte
+}
+
+// readCIDSubsetFont 读取CID字体的原始字典及逐字形归属，不合并字体字典
+// 入参: data CFF数据
+// 返回: *cidSubsetFont 裁剪资源, error 结构错误或不支持的字典
+func readCIDSubsetFont(data []byte) (*cidSubsetFont, error) {
+	if !isBareCFFData(data) {
+		return nil, fmt.Errorf("invalid CFF header")
+	}
+	names, end, err := readType2Index(data, int(data[2]))
+	if err != nil || len(names) != 1 {
+		return nil, fmt.Errorf("invalid CFF name index")
+	}
+	tops, end, err := readType2Index(data, end)
+	if err != nil || len(tops) != 1 {
+		return nil, fmt.Errorf("invalid CFF top index")
+	}
+	strings, end, err := readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	globals, _, err := readType2Index(data, end)
+	if err != nil {
+		return nil, err
+	}
+	top, err := readCFFDict(tops[0])
+	if err != nil {
+		return nil, err
+	}
+	ros := top[1230]
+	if len(ros) != 3 {
+		return nil, fmt.Errorf("invalid CFF ROS")
+	}
+	for index, value := range ros {
+		limit := float64(math.MaxInt32)
+		if index < 2 {
+			limit = float64(min(64999, 390+len(strings)))
+		}
+		if !finite(value) || value < 0 || value > limit || value != math.Trunc(value) {
+			return nil, fmt.Errorf("invalid CFF ROS operand")
+		}
+	}
+	for op := range top {
+		switch op {
+		case 0, 1, 2, 3, 4, 5, 13, 14, 15, 17, 1200, 1201, 1202, 1203, 1204, 1205, 1206, 1207, 1208, 1230, 1231, 1232, 1233, 1234, 1236, 1237:
+		default:
+			return nil, fmt.Errorf("unsupported CID CFF top operator %d", op)
+		}
+	}
+	if value, ok := top[1206]; ok && (len(value) != 1 || value[0] != 2) {
+		return nil, fmt.Errorf("unsupported CFF charstring type")
+	}
+	if _, err := readCFFMatrix(top, [6]float64{.001, 0, 0, .001, 0, 0}); err != nil {
+		return nil, err
+	}
+	charOffset, err := cffDictOffset(data, top, 17)
+	if err != nil {
+		return nil, err
+	}
+	chars, _, err := readType2Index(data, charOffset)
+	if err != nil || len(chars) == 0 {
+		return nil, fmt.Errorf("invalid CFF charstrings")
+	}
+	charsetOffset, err := cffDictOffset(data, top, 15)
+	if err != nil || charsetOffset <= 2 {
+		return nil, fmt.Errorf("invalid CID CFF charset offset")
+	}
+	cids, err := parseCFFCharset(data, charsetOffset, len(chars))
+	if err != nil {
+		return nil, err
+	}
+	fdOffset, err := cffDictOffset(data, top, 1236)
+	if err != nil {
+		return nil, err
+	}
+	fds, _, err := readType2Index(data, fdOffset)
+	if err != nil || len(fds) == 0 || len(fds) > 256 {
+		return nil, fmt.Errorf("invalid CFF font dictionary count")
+	}
+	selectOffset, err := cffDictOffset(data, top, 1237)
+	if err != nil {
+		return nil, err
+	}
+	selects, err := readType2FDSelect(data, selectOffset, len(chars), len(fds))
+	if err != nil {
+		return nil, err
+	}
+	if data[selectOffset] == 3 && binary.BigEndian.Uint16(data[selectOffset+3:]) != 0 {
+		return nil, fmt.Errorf("CFF FDSelect must include glyph zero")
+	}
+	font := &cidSubsetFont{
+		prefix:  append(bytes.Clone(data[:int(data[2])]), encodeCFFIndex(names)...),
+		strings: strings, top: top, selects: selects, charset: encodeCFFSubsetCharset(cids),
+		dicts: make([]cffDict, len(fds)), private: make([]cffDict, len(fds)), fonts: make([]*type2Font, len(fds)),
+	}
+	for index, fd := range fds {
+		dict, err := readCFFDict(fd)
+		if err != nil {
+			return nil, err
+		}
+		for op := range dict {
+			switch op {
+			case 18, 1207, 1238:
+			default:
+				return nil, fmt.Errorf("unsupported CFF font dictionary operator %d", op)
+			}
+		}
+		if _, err := readCFFMatrix(dict, [6]float64{1, 0, 0, 1, 0, 0}); err != nil {
+			return nil, err
+		}
+		if len(dict[18]) != 2 {
+			return nil, fmt.Errorf("missing CFF private dictionary")
+		}
+		resource := &type2Font{data: data, chars: chars, globals: globals, seed: 1, cid: true}
+		private, err := readType2Private(data, dict[18], resource)
+		if err != nil {
+			return nil, err
+		}
+		if _, err := encodeCFFSubsetPrivate(private); err != nil {
+			return nil, err
+		}
+		font.dicts[index], font.private[index], font.fonts[index] = dict, private, resource
+	}
+	return font, nil
+}
+
+// write 重建CID字体偏移，保留CID映射、字体矩阵及各字典的私有参数
+// 入参: chars 裁剪后的字形程序
+// 返回: []byte CFF数据, error 偏移或字典错误
+func (f *cidSubsetFont) write(chars [][]byte) ([]byte, error) {
+	suffix := append(encodeCFFIndex(f.strings), encodeCFFIndex(f.fonts[0].globals)...)
+	selects := encodeCFFSubsetFDSelect(f.selects)
+	programs := encodeCFFIndex(chars)
+	private := make([][]byte, len(f.fonts))
+	locals := make([][]byte, len(f.fonts))
+	fds := make([][]byte, len(f.fonts))
+	for index, font := range f.fonts {
+		var err error
+		private[index], err = encodeCFFSubsetPrivate(f.private[index])
+		if err != nil {
+			return nil, err
+		}
+		if _, ok := f.private[index][19]; ok {
+			locals[index] = encodeCFFIndex(font.locals)
+		}
+		fds[index] = encodeCFFDict(f.dicts[index])
+	}
+	for range 16 {
+		top := encodeCFFIndex([][]byte{encodeCFFDict(f.top)})
+		array := encodeCFFIndex(fds)
+		offset := len(f.prefix) + len(top) + len(suffix)
+		f.top[15] = []float64{float64(offset)}
+		offset += len(f.charset)
+		f.top[1237] = []float64{float64(offset)}
+		offset += len(selects)
+		f.top[17] = []float64{float64(offset)}
+		offset += len(programs)
+		f.top[1236] = []float64{float64(offset)}
+		offset += len(array)
+		for index := range f.fonts {
+			f.dicts[index][18] = []float64{float64(len(private[index])), float64(offset)}
+			fds[index] = encodeCFFDict(f.dicts[index])
+			offset += len(private[index]) + len(locals[index])
+		}
+		updatedTop := encodeCFFIndex([][]byte{encodeCFFDict(f.top)})
+		updatedArray := encodeCFFIndex(fds)
+		if len(updatedTop) != len(top) || len(updatedArray) != len(array) {
+			continue
+		}
+		result := make([]byte, 0, offset)
+		for _, part := range [][]byte{f.prefix, updatedTop, suffix, f.charset, selects, programs, updatedArray} {
+			result = append(result, part...)
+		}
+		for index := range f.fonts {
+			result = append(result, private[index]...)
+			result = append(result, locals[index]...)
+		}
+		return result, nil
+	}
+	return nil, fmt.Errorf("CID CFF offsets did not converge")
+}
+
+// encodeCFFSubsetFDSelect 选择较短的逐字形或分段格式保存字体字典归属
+// 入参: selects 字形所属字典
+// 返回: []byte FDSelect数据
+func encodeCFFSubsetFDSelect(selects []int) []byte {
+	ranges := []byte{3, 0, 0}
+	count := 0
+	for gid, fd := range selects {
+		if gid == 0 || fd != selects[gid-1] {
+			ranges = binary.BigEndian.AppendUint16(ranges, uint16(gid))
+			ranges = append(ranges, byte(fd))
+			count++
+		}
+	}
+	binary.BigEndian.PutUint16(ranges[1:], uint16(count))
+	ranges = binary.BigEndian.AppendUint16(ranges, uint16(len(selects)))
+	if len(ranges) < len(selects)+1 {
+		return ranges
+	}
+	result := make([]byte, len(selects)+1)
+	for gid, fd := range selects {
+		result[gid+1] = byte(fd)
+	}
+	return result
+}

ofdgo_font_cff_compact.go

@@ -0,0 +1,339 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"slices"
+)
+
+// compactCFFGlyphs 重排已裁剪字体的字形，同步字符集、编码和字体字典归属
+// 入参: data 已裁剪的CFF数据, keep 保留的原字形编号
+// 返回: []byte 紧凑CFF数据, []uint16 新编号对应的原编号, error 结构或编码错误
+func compactCFFGlyphs(data []byte, keep map[uint16]bool) ([]byte, []uint16, error) {
+	ids := []uint16{0}
+	for gid, used := range keep {
+		if used && gid != 0 {
+			ids = append(ids, gid)
+		}
+	}
+	slices.Sort(ids)
+	font, err := readType2Font(data)
+	if err == nil {
+		sids, _, _, _, ok := getCFFCharsetInfo(data, len(font.chars))
+		if !ok {
+			return nil, nil, fmt.Errorf("invalid CFF charset")
+		}
+		_, end, _ := readType2Index(data, int(data[2]))
+		tops, _, _ := readType2Index(data, end)
+		dict, _ := readCFFDict(tops[0])
+		encoding, err := cffSubsetEncoding(data, dict)
+		if err != nil {
+			return nil, nil, err
+		}
+		if encoding != nil {
+			codes, err := readCFFSubsetEncoding(encoding, sids)
+			if err != nil {
+				return nil, nil, err
+			}
+			ordered := []uint16{0}
+			seen := map[uint16]bool{0: true}
+			for _, gid := range codes {
+				if keep[gid] && !seen[gid] {
+					ordered = append(ordered, gid)
+					seen[gid] = true
+				}
+			}
+			for _, gid := range ids {
+				if !seen[gid] {
+					ordered = append(ordered, gid)
+				}
+			}
+			ids = ordered
+		}
+		chars := make([][]byte, len(ids))
+		for index, gid := range ids {
+			if int(gid) >= len(font.chars) {
+				return nil, nil, fmt.Errorf("CFF glyph index out of range")
+			}
+			chars[index] = font.chars[gid]
+		}
+		result, err := rebuildNamedCFF(data, font, chars, ids)
+		return result, ids, err
+	}
+	cid, err := readCIDSubsetFont(data)
+	if err != nil {
+		return nil, nil, err
+	}
+	cids, _, _, _, ok := getCFFCharsetInfo(data, len(cid.selects))
+	if !ok {
+		return nil, nil, fmt.Errorf("invalid CID CFF charset")
+	}
+	chars := make([][]byte, len(ids))
+	selected := make([]int, len(ids))
+	selects := make([]int, len(ids))
+	dicts, private, fonts := []cffDict{}, []cffDict{}, []*type2Font{}
+	remap := make(map[int]int)
+	for index, gid := range ids {
+		if int(gid) >= len(cid.selects) {
+			return nil, nil, fmt.Errorf("CFF glyph index out of range")
+		}
+		fd := cid.selects[gid]
+		mapped, exists := remap[fd]
+		if !exists {
+			mapped = len(fonts)
+			remap[fd] = mapped
+			dicts = append(dicts, cid.dicts[fd])
+			private = append(private, cid.private[fd])
+			fonts = append(fonts, cid.fonts[fd])
+		}
+		chars[index], selected[index], selects[index] = cid.fonts[fd].chars[gid], cids[gid], mapped
+	}
+	cid.dicts, cid.private, cid.fonts = dicts, private, fonts
+	cid.charset, cid.selects = encodeCFFSubsetCharset(selected), selects
+	result, err := cid.write(chars)
+	return result, ids, err
+}
+
+// compactCFFTables 重建按字形编号索引的度量和字符映射，不保留旧编号的布局表
+// 入参: font 原字体, cff 紧凑CFF数据, ids 新编号对应的原编号
+// 返回: []byte 独立OpenType字体, error 封装错误
+func compactCFFTables(font *sfntFont, cff []byte, ids []uint16) ([]byte, error) {
+	tables := make(map[string][]byte)
+	for _, tag := range []string{"head", "hhea", "maxp", "OS/2", "post", "name", "vhea", "gasp"} {
+		if data := font.Tables[tag]; data != nil {
+			tables[tag] = bytes.Clone(data)
+		}
+	}
+	var hmtx, vmtx []byte
+	mapping := make(map[rune]uint16)
+	for index, gid := range ids {
+		hmtx = binary.BigEndian.AppendUint16(hmtx, font.GlyphAdvance(gid))
+		hmtx = binary.BigEndian.AppendUint16(hmtx, uint16(font.sideBearing(gid, false)))
+		if font.vertical != 0 {
+			vmtx = binary.BigEndian.AppendUint16(vmtx, font.GlyphVerticalAdvance(gid))
+			vmtx = binary.BigEndian.AppendUint16(vmtx, uint16(font.sideBearing(gid, true)))
+		}
+		for _, char := range font.glyphCharacters(gid) {
+			mapping[char] = uint16(index)
+		}
+	}
+	tables["CFF "], tables["hmtx"] = cff, hmtx
+	tables["cmap"] = buildCmapTable(uint16(len(ids)), mapping)
+	binary.BigEndian.PutUint16(tables["hhea"][34:], uint16(len(ids)))
+	binary.BigEndian.PutUint16(tables["maxp"][4:], uint16(len(ids)))
+	if len(tables["post"]) >= 32 {
+		tables["post"] = tables["post"][:32]
+		binary.BigEndian.PutUint32(tables["post"], 0x30000)
+	}
+	if font.vertical != 0 {
+		tables["vmtx"] = vmtx
+		binary.BigEndian.PutUint16(tables["vhea"][34:], uint16(len(ids)))
+	}
+	if data := font.Tables["VORG"]; data != nil {
+		var err error
+		tables["VORG"], err = compactCFFVerticalOrigins(data, font.NumGlyphs(), ids)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return serializeOTF(tables)
+}
+
+// compactCFFVerticalOrigins 重排CFF字体的逐字形纵向原点，保留默认原点
+// 入参: data VORG表, count 原字形数, ids 新编号对应的原编号
+// 返回: []byte 重建的VORG表, error 表结构或记录顺序错误
+func compactCFFVerticalOrigins(data []byte, count uint16, ids []uint16) ([]byte, error) {
+	if len(data) < 8 || binary.BigEndian.Uint32(data) != 0x10000 {
+		return nil, fmt.Errorf("invalid CFF vertical origin header")
+	}
+	length := int(binary.BigEndian.Uint16(data[6:]))
+	if length > (len(data)-8)/4 {
+		return nil, fmt.Errorf("truncated CFF vertical origins")
+	}
+	origins := make(map[uint16]uint16, length)
+	previous := -1
+	for index := range length {
+		pos := 8 + index*4
+		gid := binary.BigEndian.Uint16(data[pos:])
+		if gid >= count || int(gid) <= previous {
+			return nil, fmt.Errorf("invalid CFF vertical origin glyph")
+		}
+		origins[gid] = binary.BigEndian.Uint16(data[pos+2:])
+		previous = int(gid)
+	}
+	result := bytes.Clone(data[:8])
+	for index, gid := range ids {
+		if origin, ok := origins[gid]; ok {
+			result = binary.BigEndian.AppendUint16(result, uint16(index))
+			result = binary.BigEndian.AppendUint16(result, origin)
+		}
+	}
+	binary.BigEndian.PutUint16(result[6:], uint16((len(result)-8)/4))
+	return result, nil
+}
+
+// encodeCFFSubsetCharset 选择最短的标准字符集格式，保持SID或CID及字形顺序
+// 入参: ids 按字形编号排列的SID或CID，包含.notdef
+// 返回: []byte 字符集数据
+func encodeCFFSubsetCharset(ids []int) []byte {
+	sizes := [3]int{1 + 2*(len(ids)-1), 1, 1}
+	for first := 1; first < len(ids); {
+		end := first + 1
+		for end < len(ids) && ids[end] == ids[end-1]+1 {
+			end++
+		}
+		sizes[1] += 3 * ((end - first + 255) / 256)
+		sizes[2] += 4
+		first = end
+	}
+	format := 0
+	for index, size := range sizes {
+		if size < sizes[format] {
+			format = index
+		}
+	}
+	result := make([]byte, 1, sizes[format])
+	result[0] = byte(format)
+	for first := 1; first < len(ids); {
+		end := first + 1
+		if format != 0 {
+			limit := len(ids)
+			if format == 1 {
+				limit = min(limit, first+256)
+			}
+			for end < limit && ids[end] == ids[end-1]+1 {
+				end++
+			}
+		}
+		result = binary.BigEndian.AppendUint16(result, uint16(ids[first]))
+		if format == 1 {
+			result = append(result, byte(end-first-1))
+		} else if format == 2 {
+			result = binary.BigEndian.AppendUint16(result, uint16(end-first-1))
+		}
+		first = end
+	}
+	return result
+}
+
+// readCFFSubsetEncoding 解析自定义编码及补充映射，校验重复编码和字形归属
+// 入参: data 编码数据, sids 原字符集
+// 返回: [256]uint16 编码对应的字形编号, error 编码结构错误
+func readCFFSubsetEncoding(data []byte, sids []int) ([256]uint16, error) {
+	var codes [256]uint16
+	if len(data) < 2 {
+		return codes, fmt.Errorf("truncated CFF encoding")
+	}
+	pos, gid := 2, 1
+	for index := 0; index < int(data[1]); index++ {
+		if pos >= len(data) {
+			return codes, fmt.Errorf("truncated CFF encoding")
+		}
+		first, count := int(data[pos]), 1
+		pos++
+		switch data[0] & 0x7f {
+		case 0:
+		case 1:
+			if pos >= len(data) {
+				return codes, fmt.Errorf("truncated CFF encoding range")
+			}
+			count += int(data[pos])
+			pos++
+		default:
+			return codes, fmt.Errorf("invalid CFF encoding format")
+		}
+		if first+count > len(codes) || gid+count > len(sids) {
+			return codes, fmt.Errorf("CFF encoding range out of bounds")
+		}
+		for code := first; code < first+count; code++ {
+			if codes[code] != 0 {
+				return codes, fmt.Errorf("duplicate CFF encoding")
+			}
+			codes[code] = uint16(gid)
+			gid++
+		}
+	}
+	if data[0]&0x80 != 0 {
+		if pos >= len(data) {
+			return codes, fmt.Errorf("truncated CFF encoding supplements")
+		}
+		count := int(data[pos])
+		pos++
+		if count > (len(data)-pos)/3 {
+			return codes, fmt.Errorf("truncated CFF encoding supplements")
+		}
+		for range count {
+			code, sid := data[pos], int(binary.BigEndian.Uint16(data[pos+1:]))
+			pos += 3
+			mapped := slices.Index(sids[:gid], sid)
+			if codes[code] != 0 || mapped <= 0 {
+				return codes, fmt.Errorf("invalid CFF supplemental glyph")
+			}
+			codes[code] = uint16(mapped)
+		}
+	}
+	if data[0]&0x7f > 1 || pos != len(data) {
+		return codes, fmt.Errorf("invalid CFF encoding length or format")
+	}
+	return codes, nil
+}
+
+// encodeCFFSubsetEncoding 按新字形顺序重建主编码及同字形的补充编码
+// 入参: codes 原编码映射, sids 原字符集, ids 新编号对应的原编号
+// 返回: []byte 编码数据, error 字形顺序不满足编码约束
+func encodeCFFSubsetEncoding(codes [256]uint16, sids []int, ids []uint16) ([]byte, error) {
+	var base, supplements []byte
+	encodings := make(map[uint16][]byte)
+	for code, gid := range codes {
+		if gid != 0 {
+			encodings[gid] = append(encodings[gid], byte(code))
+		}
+	}
+	unencoded := false
+	for _, gid := range ids[1:] {
+		values := encodings[gid]
+		if len(values) == 0 {
+			unencoded = true
+		} else if unencoded {
+			return nil, fmt.Errorf("CFF encoded glyph follows unencoded glyph")
+		} else {
+			base = append(base, values[0])
+			for _, code := range values[1:] {
+				supplements = append(supplements, code)
+				supplements = binary.BigEndian.AppendUint16(supplements, uint16(sids[gid]))
+			}
+		}
+	}
+	var result []byte
+	if len(base) == 256 {
+		for index, code := range base {
+			if int(code) != index {
+				return nil, fmt.Errorf("CFF encoding exceeds format zero capacity")
+			}
+		}
+		result = []byte{1, 1, 0, 255}
+	} else {
+		result = append([]byte{0, byte(len(base))}, base...)
+	}
+	if len(supplements) != 0 {
+		result[0] |= 0x80
+		result = append(result, byte(len(supplements)/3))
+		result = append(result, supplements...)
+	}
+	return result, nil
+}

ofdgo_font_cff_subset.go

@@ -16,15 +16,14 @@ package ofdgo
 
 import (
 	"bytes"
-	"encoding/binary"
 	"fmt"
 	"maps"
 )
 
-// subsetNamedCFFFont 裁剪非CID的CFF字体，保留字形编号、组合组件和度量
+// subsetCFFFont 裁剪CFF字体，保留组合组件和度量，按需重排字形
-// 入参: sfnt 已解析字体, glyphs 使用的字形
+// 入参: sfnt 已解析字体, glyphs 使用的字形, preserve 是否保留原字形编号
 // 返回: []byte 字体子集, error 裁剪错误
-func subsetNamedCFFFont(sfnt *sfntFont, glyphs []uint16) ([]byte, error) {
+func subsetCFFFont(sfnt *sfntFont, glyphs []uint16, preserve bool) ([]byte, error) {
 	keep := map[uint16]bool{0: true}
 	for _, gid := range glyphs {
 		if gid >= sfnt.NumGlyphs() {
@@ -36,6 +35,11 @@ func subsetNamedCFFFont(sfnt *sfntFont, glyphs []uint16) ([]byte, error) {
 	if err != nil {
 		return bytes.Clone(sfnt.Write()), nil
 	}
+	if !preserve {
+		if compact, ids, err := compactCFFGlyphs(data, keep); err == nil {
+			return compactCFFTables(sfnt, compact, ids)
+		}
+	}
 	tables := maps.Clone(sfnt.Tables)
 	tables["CFF "] = data
 	mapping := make(map[rune]uint16)
@@ -52,60 +56,106 @@ func subsetNamedCFFFont(sfnt *sfntFont, glyphs []uint16) ([]byte, error) {
 }
 
 // subsetCFFCharstrings 清空未引用的Type2轮廓及子程序，保留原字宽、提示和编号
-// 入参: data 非CID的CFF数据, keep 保留的字形，调用后包含组合组件
+// 入参: data CFF数据, keep 保留的字形，调用后包含组合组件
 // 返回: []byte 重建的CFF数据, error 结构或依赖错误
 func subsetCFFCharstrings(data []byte, keep map[uint16]bool) ([]byte, error) {
 	font, err := readType2Font(data)
+	if err != nil {
+		cid, err := readCIDSubsetFont(data)
 		if err != nil {
 			return nil, err
 		}
+		chars, err := subsetType2Programs(cid.fonts, cid.selects, keep)
+		if err != nil {
+			return nil, err
+		}
+		return cid.write(chars)
+	}
+	chars, err := subsetType2Programs([]*type2Font{font}, nil, keep)
+	if err != nil {
+		return nil, err
+	}
+	return rebuildNamedCFF(data, font, chars, nil)
+}
+
+// subsetType2Programs 按字形所属字典收集子程序依赖并清空未使用的轮廓
+// 入参: fonts 执行资源, selects 字形所属字典，单字典时可为空, keep 保留的字形
+// 返回: [][]byte 字形程序, error 执行或字宽错误
+func subsetType2Programs(fonts []*type2Font, selects []int, keep map[uint16]bool) ([][]byte, error) {
 	keep[0] = true
-	locals := make([]bool, len(font.locals))
+	programs := fonts[0].chars
-	globals := make([]bool, len(font.globals))
+	locals := make([][]bool, len(fonts))
+	empty := make([]map[float64][]byte, len(fonts))
+	for index, font := range fonts {
+		locals[index] = make([]bool, len(font.locals))
+		empty[index] = make(map[float64][]byte)
+	}
+	globals := make([]bool, len(fonts[0].globals))
 	var stack [48]float64
 	for gid := range keep {
-		if int(gid) >= len(font.chars) {
+		if int(gid) >= len(programs) {
 			return nil, fmt.Errorf("CFF glyph index out of range")
 		}
+		fd := 0
+		if selects != nil {
+			fd = selects[gid]
+		}
+		font := fonts[fd]
 		steps := 0
-		state := type2State{font: font, args: stack[:0], width: font.def, seed: font.seed + uint64(gid), steps: &steps, dependencies: keep, localUsage: locals, globalUsage: globals}
+		state := type2State{font: font, args: stack[:0], width: font.def, seed: font.seed + uint64(gid), steps: &steps, dependencies: keep, localUsage: locals[fd], globalUsage: globals}
 		if _, err := state.run(font.chars[gid], 0); err != nil {
 			return nil, err
 		}
 	}
-	chars := make([][]byte, len(font.chars))
+	chars := make([][]byte, len(programs))
-	empty := make(map[float64][]byte)
+	for gid, program := range programs {
-	for gid, program := range font.chars {
 		if keep[uint16(gid)] {
 			chars[gid] = program
 			continue
 		}
+		fd := 0
+		if selects != nil {
+			fd = selects[gid]
+		}
+		font := fonts[fd]
 		steps := 0
 		state := type2State{font: font, args: stack[:0], width: font.def, widthOnly: true, seed: font.seed + uint64(gid), steps: &steps, dependencies: keep}
 		if _, err := state.run(program, 0); err != nil {
 			return nil, err
 		}
-		if encoded, ok := empty[state.width]; ok {
+		if encoded, ok := empty[fd][state.width]; ok {
 			chars[gid] = encoded
 			continue
 		}
 		var encoded bytes.Buffer
 		if state.width != font.def {
 			value := state.width - font.nominal
-			if err := encodeType2Number(&encoded, value); err != nil {
+			divisor := 1
+			if value < -32768 || value >= 32768 {
+				divisor = 2
+			}
+			for range divisor {
+				if err := encodeType2Number(&encoded, value/float64(divisor)); err != nil {
 					return nil, err
 				}
-			if parseNumberType2(encoded.Bytes(), 0) != value {
+			}
+			if parseNumberType2(encoded.Bytes(), 0)*float64(divisor) != value {
 				return nil, fmt.Errorf("CFF width cannot be represented exactly")
 			}
+			if divisor == 2 {
+				encoded.Write([]byte{12, 10})
+			}
 		}
 		encoded.WriteByte(14)
 		chars[gid] = encoded.Bytes()
-		empty[state.width] = chars[gid]
+		empty[fd][state.width] = chars[gid]
 	}
-	font.locals = subsetCFFSubroutines(font.locals, locals)
+	globalPrograms := subsetCFFSubroutines(fonts[0].globals, globals)
-	font.globals = subsetCFFSubroutines(font.globals, globals)
+	for index, font := range fonts {
-	return rebuildNamedCFF(data, font, chars)
+		font.locals = subsetCFFSubroutines(font.locals, locals[index])
+		font.globals = globalPrograms
+	}
+	return chars, nil
 }
 
 // subsetCFFSubroutines 将未引用的子程序替换为空返回，保持调用编号及偏移基数
@@ -125,9 +175,9 @@ func subsetCFFSubroutines(programs [][]byte, used []bool) [][]byte {
 }
 
 // rebuildNamedCFF 重建非CID的CFF偏移，保留字符集、编码和私有提示参数
-// 入参: data 原始CFF数据, font 执行资源, chars 替换后的字形程序
+// 入参: data 原始CFF数据, font 执行资源, chars 替换后的字形程序, ids 字形重排顺序，nil时保留原编号
 // 返回: []byte 重建的CFF数据, error 不支持的结构
-func rebuildNamedCFF(data []byte, font *type2Font, chars [][]byte) ([]byte, error) {
+func rebuildNamedCFF(data []byte, font *type2Font, chars [][]byte, ids []uint16) ([]byte, error) {
 	names, end, err := readType2Index(data, int(data[2]))
 	if err != nil {
 		return nil, err
@@ -151,35 +201,39 @@ func rebuildNamedCFF(data []byte, font *type2Font, chars [][]byte) ([]byte, erro
 			return nil, fmt.Errorf("unsupported CFF top operator %d", op)
 		}
 	}
-	sids, _, _, _, ok := getCFFCharsetInfo(data, len(chars))
+	sids, _, _, _, ok := getCFFCharsetInfo(data, len(font.chars))
 	if !ok {
 		return nil, fmt.Errorf("invalid CFF charset")
 	}
-	charset := []byte{0}
-	for _, sid := range sids[1:] {
-		charset = binary.BigEndian.AppendUint16(charset, uint16(sid))
-	}
 	encoding, err := cffSubsetEncoding(data, dict)
 	if err != nil {
 		return nil, err
 	}
+	if ids != nil {
+		if encoding != nil {
+			codes, err := readCFFSubsetEncoding(encoding, sids)
+			if err != nil {
+				return nil, err
+			}
+			encoding, err = encodeCFFSubsetEncoding(codes, sids, ids)
+			if err != nil {
+				return nil, err
+			}
+		}
+		selected := make([]int, len(ids))
+		for index, gid := range ids {
+			selected[index] = sids[gid]
+		}
+		sids = selected
+	}
+	charset := encodeCFFSubsetCharset(sids)
 	private, err := readType2Private(data, dict[18], &type2Font{})
 	if err != nil {
 		return nil, err
 	}
-	for op := range private {
+	privateData, err := encodeCFFSubsetPrivate(private)
-		switch op {
+	if err != nil {
-		case 6, 7, 8, 9, 10, 11, 19, 20, 21, 1209, 1210, 1211, 1212, 1213, 1214, 1217, 1218, 1219:
+		return nil, err
-		default:
-			return nil, fmt.Errorf("unsupported CFF private operator %d", op)
-		}
-	}
-	privateData := encodeCFFDict(private)
-	if _, ok := private[19]; ok {
-		for private[19][0] != float64(len(privateData)) {
-			private[19] = []float64{float64(len(privateData))}
-			privateData = encodeCFFDict(private)
-		}
 	}
 	prefix := bytes.Clone(data[:int(data[2])])
 	prefix = append(prefix, encodeCFFIndex(names)...)
@@ -212,6 +266,28 @@ func rebuildNamedCFF(data []byte, font *type2Font, chars [][]byte) ([]byte, erro
 	return nil, fmt.Errorf("CFF dictionary offsets did not converge")
 }
 
+// encodeCFFSubsetPrivate 保留私有字典参数，将局部子程序安排在字典之后
+// 入参: private 私有字典
+// 返回: []byte 字典数据, error 不支持的参数或偏移错误
+func encodeCFFSubsetPrivate(private cffDict) ([]byte, error) {
+	for op := range private {
+		switch op {
+		case 6, 7, 8, 9, 10, 11, 19, 20, 21, 1209, 1210, 1211, 1212, 1213, 1214, 1217, 1218, 1219:
+		default:
+			return nil, fmt.Errorf("unsupported CFF private operator %d", op)
+		}
+	}
+	for range 16 {
+		data := encodeCFFDict(private)
+		value, ok := private[19]
+		if !ok || len(value) == 1 && value[0] == float64(len(data)) {
+			return data, nil
+		}
+		private[19] = []float64{float64(len(data))}
+	}
+	return nil, fmt.Errorf("CFF private offset did not converge")
+}
+
 // cffSubsetEncoding 读取自定义CFF编码及补充映射，预定义编码无需复制
 // 入参: data CFF数据, dict 顶层字典
 // 返回: []byte 编码数据, error 编码格式错误

ofdgo_font_resource_sfnt.go

@@ -102,7 +102,11 @@ func sfntSubsettable(sfnt *sfntFont) bool {
 			return false
 		}
 		font, err := readType2Font(sfnt.Tables["CFF "])
-		return err == nil && len(font.chars) == int(sfnt.NumGlyphs()) || staticCFFPrograms(sfnt) != nil
+		if err == nil {
+			return len(font.chars) == int(sfnt.NumGlyphs())
+		}
+		cid, err := readCIDSubsetFont(sfnt.Tables["CFF "])
+		return err == nil && len(cid.fonts[0].chars) == int(sfnt.NumGlyphs())
 	}
 	return sfnt.IsTrueType && (sfnt.Tables["fvar"] == nil || variableSFNTSubsettable(sfnt))
 }
@@ -166,13 +170,14 @@ func subsetSFNTFont(data []byte, glyphs []uint16, mapped bool) ([]byte, error) {
 		return bytes.Clone(data), nil
 	}
 	if sfnt.IsCFF {
-		if font, err := readType2Font(sfnt.Tables["CFF "]); err == nil {
+		count, err := parseCFFAndCountGlyphs(sfnt.Tables["CFF "])
-			if len(font.chars) != int(sfnt.NumGlyphs()) {
+		if err != nil {
+			return nil, err
+		}
+		if count != int(sfnt.NumGlyphs()) {
 			return nil, fmt.Errorf("CFF glyph count does not match maxp")
 		}
-			return subsetNamedCFFFont(sfnt, glyphs)
+		return subsetCFFFont(sfnt, glyphs, mapped)
-		}
-		return subsetStaticCFFFont(sfnt, glyphs)
 	}
 	if sfnt.Tables["fvar"] != nil {
 		return subsetVariableSFNTFont(sfnt, glyphs)
@@ -203,7 +208,7 @@ func subsetSFNTFont(data []byte, glyphs []uint16, mapped bool) ([]byte, error) {
 	return subsetCompactSFNTFont(sfnt, glyphs)
 }
 
-// subsetSourceSFNTFont 裁剪静态TrueType或非CID的CFF原有字体，保留字形编号、组合依赖、度量和提示指令
+// subsetSourceSFNTFont 裁剪静态TrueType或CFF原有字体，保留字形编号、组合依赖、度量和提示指令
 // 集合、字形替换、可变、彩色和未知表保持原样，不对不完整的引用或异常字体猜测修复
 // 入参: data 字体数据, usage 全包用字记录
 // 返回: []byte 更小的字体子集，无确定收益时为空
@@ -217,7 +222,7 @@ func subsetSourceSFNTFont(data []byte, usage *editorFontUsage) []byte {
 	}
 	for tag := range sfnt.Tables {
 		switch tag {
-		case "cmap", "head", "hhea", "hmtx", "maxp", "OS/2", "post", "name", "glyf", "loca", "CFF ", "cvt ", "fpgm", "prep", "gasp", "kern", "vhea", "vmtx", "hdmx", "LTSH", "VDMX", "GDEF", "GPOS", "DSIG", "FFTM":
+		case "cmap", "head", "hhea", "hmtx", "maxp", "OS/2", "post", "name", "glyf", "loca", "CFF ", "cvt ", "fpgm", "prep", "gasp", "kern", "vhea", "vmtx", "VORG", "hdmx", "LTSH", "VDMX", "GDEF", "GPOS", "DSIG", "FFTM":
 		default:
 			return nil
 		}
@@ -250,8 +255,8 @@ func subsetSourceSFNTFont(data []byte, usage *editorFontUsage) []byte {
 		}
 	}
 	if sfnt.IsCFF {
-		font, err := readType2Font(sfnt.Tables["CFF "])
+		count, err := parseCFFAndCountGlyphs(sfnt.Tables["CFF "])
-		if err != nil || len(font.chars) != int(sfnt.NumGlyphs()) {
+		if err != nil || count != int(sfnt.NumGlyphs()) {
 			return nil
 		}
 		cff, err := subsetCFFCharstrings(sfnt.Tables["CFF "], glyphs)

ofdgo_font_shape.go

@@ -35,6 +35,9 @@ import (
 	xlanguage "golang.org/x/text/language"
 )
 
+// fontShapingBufferLimit 限制字体实例长期保留的字形缓冲容量
+const fontShapingBufferLimit = 4096
+
 // fontShaper 使用字体度量和原始数据提供可配置塑形，不依赖绘图后端
 type fontShaper struct {
 	metrics     FontMetrics
@@ -61,8 +64,32 @@ func (f *fontShaper) ShapeTextWithOptions(value string, size float64, options Te
 	if !rasterPositive(size) || !utf8.ValidString(value) {
 		return nil, fmt.Errorf("invalid shaping text or size")
 	}
-	for _, char := range value {
+	runes := []rune(value)
-		if unicode.IsControl(char) || char == '\u2028' || char == '\u2029' {
+	return f.shapeTextRun(runes, 0, len(runes), size, options)
+}
+
+// ShapeTextRun 利用原文上下文塑形指定区间，保留原文簇索引
+// 入参: value 已校验的原文符文, start 起始符文索引, end 结束符文索引, size 毫米字号, options 已分段的塑形选项
+// 返回: []ShapedGlyph 原文簇索引及区间内定位字形, error 区间、字符或选项错误
+func (f *fontShaper) ShapeTextRun(value []rune, start, end int, size float64, options TextShapeOptions) ([]ShapedGlyph, error) {
+	if options.Bidi {
+		return nil, fmt.Errorf("bidirectional segmentation is not valid for an individual shaping run")
+	}
+	return f.shapeTextRun(value, start, end, size, options)
+}
+
+// shapeTextRun 共用完整行与局部区间的选项校验、字体初始化及字形塑形
+// 入参: runes 原文符文, start 起始符文索引, end 结束符文索引, size 毫米字号, options 塑形选项
+// 返回: []ShapedGlyph 定位字形, error 字体、区间或选项错误
+func (f *fontShaper) shapeTextRun(runes []rune, start, end int, size float64, options TextShapeOptions) ([]ShapedGlyph, error) {
+	if !rasterPositive(size) {
+		return nil, fmt.Errorf("invalid shaping size")
+	}
+	if start < 0 || end < start || end > len(runes) {
+		return nil, fmt.Errorf("invalid shaping text range")
+	}
+	for _, char := range runes[start:end] {
+		if !utf8.ValidRune(char) || unicode.IsControl(char) || char == '\u2028' || char == '\u2029' {
 			return nil, fmt.Errorf("shaping requires a single text line")
 		}
 	}
@@ -113,6 +140,9 @@ func (f *fontShaper) ShapeTextWithOptions(value string, size float64, options Te
 			features = append(features, feature)
 		}
 	}
+	if start == end {
+		return nil, nil
+	}
 	f.shapeMu.Lock()
 	defer f.shapeMu.Unlock()
 	if f.shapeFont == nil {
@@ -125,24 +155,32 @@ func (f *fontShaper) ShapeTextWithOptions(value string, size float64, options Te
 		f.shapeBuffer = harfbuzz.NewBuffer()
 	}
 	if options.Bidi {
-		return f.shapeBidiText([]rune(value), size, props, features)
+		return f.shapeBidiText(runes, size, props, features)
 	}
 	buffer := f.shapeBuffer
 	buffer.Clear()
+	defer f.releaseShapeBuffer()
 	buffer.Props = props
-	runes := []rune(value)
+	buffer.AddRunes(runes, start, end-start)
-	buffer.AddRunes(runes, 0, len(runes))
 	buffer.GuessSegmentProperties()
 	buffer.Shape(f.shapeFont, features)
 	unit := size / float64(f.metrics.UnitsPerEm())
 	result := make([]ShapedGlyph, len(buffer.Info))
 	var x, y float64
+	previous, order := -1, -1
 	for i, info := range buffer.Info {
 		if info.Glyph >= typefont.GID(f.metrics.NumGlyphs()) {
 			return nil, fmt.Errorf("invalid shaped glyph index %d", info.Glyph)
 		}
+		if info.Cluster < start || info.Cluster >= end {
+			return nil, fmt.Errorf("invalid shaped cluster index %d", info.Cluster)
+		}
+		if info.Cluster != previous {
+			previous = info.Cluster
+			order++
+		}
 		position := buffer.Pos[i]
-		result[i] = ShapedGlyph{Glyph: uint16(info.Glyph), Cluster: info.Cluster,
+		result[i] = ShapedGlyph{Glyph: uint16(info.Glyph), Cluster: info.Cluster, VisualOrder: order,
 			X: (x + float64(position.XOffset)) * unit, Y: -(y + float64(position.YOffset)) * unit,
 			Advance: float64(position.XAdvance) * unit}
 		if !finite(result[i].X) || !finite(result[i].Y) || !finite(result[i].Advance) {
@@ -155,6 +193,17 @@ func (f *fontShaper) ShapeTextWithOptions(value string, size float64, options Te
 	return result, nil
 }
 
+// releaseShapeBuffer 释放原文上下文和超限缓冲，普通文本继续复用已有容量
+func (f *fontShaper) releaseShapeBuffer() {
+	buffer := f.shapeBuffer
+	if cap(buffer.Info) > fontShapingBufferLimit || cap(buffer.Pos) > fontShapingBufferLimit {
+		f.shapeBuffer = harfbuzz.NewBuffer()
+		return
+	}
+	buffer.Clear()
+	buffer.AddRunes(nil, 0, 0)
+}
+
 // ResolveFace 返回指定字体
 // 入参: char 字符
 // 返回: *typefont.Face 字体
@@ -211,12 +260,19 @@ func (f *fontShaper) shapeBidiText(runes []rune, size float64, props harfbuzz.Se
 				return nil, fmt.Errorf("invalid shaped glyph index %d", glyph.GlyphID)
 			}
 			cluster := glyph.TextIndex()
+			if cluster < 0 || cluster >= len(runes) {
+				return nil, fmt.Errorf("invalid shaped cluster index %d", cluster)
+			}
 			order, exists := visual[cluster]
 			if !exists {
 				order = len(visual)
 				visual[cluster] = order
 			}
-			result = append(result, ShapedGlyph{Glyph: uint16(glyph.GlyphID), Cluster: cluster, VisualOrder: order, X: (x + float64(glyph.XOffset)) * unit, Y: -float64(glyph.YOffset) * unit, Advance: float64(glyph.Advance) * unit})
+			shaped := ShapedGlyph{Glyph: uint16(glyph.GlyphID), Cluster: cluster, VisualOrder: order, X: (x + float64(glyph.XOffset)) * unit, Y: -float64(glyph.YOffset) * unit, Advance: float64(glyph.Advance) * unit}
+			if !finite(shaped.X) || !finite(shaped.Y) || !finite(shaped.Advance) {
+				return nil, fmt.Errorf("shaped position exceeds finite range")
+			}
+			result = append(result, shaped)
 			x += float64(glyph.Advance)
 		}
 	}

ofdgo_font_type2.go

@@ -30,6 +30,7 @@ type type2Font struct {
 	names        map[string]int
 	nominal, def float64
 	seed         uint64
+	cid          bool
 }
 
 // type2State 按Type2规范保存跨子程序共享的执行状态
@@ -489,6 +490,9 @@ func (s *type2State) run(data []byte, depth int) (bool, error) {
 // 入参: code 标准字符码, x 横向偏移, y 纵向偏移
 // 返回: error 组件或指令错误
 func (s *type2State) appendComponent(code, x, y float64) error {
+	if s.font.cid {
+		return fmt.Errorf("CID CFF cannot use StandardEncoding components")
+	}
 	if code < 0 || code > 255 || code != math.Trunc(code) || type1StandardNames[int(code)] == "" {
 		return fmt.Errorf("invalid Type2 component code")
 	}

ofdgo_pdf.go

@@ -34,7 +34,7 @@ var ErrPDFPassword = pdfgo.ErrPassword
 // RendererOptions复用渲染器字体来源和后端配置，Backends优先于其中的后端设置
 // RasterDPI指定局部合成与三维绘制精度，0沿用渲染器DPI，默认300dpi，Strict禁用局部合成
 // OnProgress按open、pages、convert及write.*阶段报告进度，total为0表示总量未知
-// ResolveFile读取PDF引用的外部媒体、附件和页面，默认不访问网络或本地路径
+// ResolveFile读取PDF引用的外部媒体、附件、页面及三维纹理，默认不访问网络或本地路径
 // ResolveReference可提供已解密的引用页面，目标阅读器由调用方维护
 // Halftones提供只读设备命名网屏，所属阅读器由调用方维护，连续色调输出不网屏化
 // Compression配置转换输出，有损模式按图片实际尺寸降采样，原始及无损模式保持完整采样
@@ -156,7 +156,12 @@ func ImportPDF(ctx context.Context, source io.ReaderAt, size int64, options PDFI
 			return nil, PDFImportReport{}, err
 		}
 	}
-	readOptions := pdfgo.ReaderOptions{Password: options.Password, PasswordUTF8: options.PasswordUTF8}
+	editor := NewEditor()
+	editor.SetRenderBackends(renderer.Backends())
+	editor.fontDirs, editor.fontFS = renderer.FontSources()
+	editor.fontSourcesCache = renderer.fontSourcesCache
+	importer := pdfImporter{ctx: ctx, editor: editor, renderer: renderer, rasterDPI: renderer.DPI, fontIDs: map[*pdfgo.Font]string{}, fonts: map[*pdfgo.Font]*pdfImportedFont{}, pages: map[pdfgo.Reference]*pdfgo.Page{}, pageIDs: map[pdfgo.Reference]string{}}
+	readOptions := pdfgo.ReaderOptions{Password: options.Password, PasswordUTF8: options.PasswordUTF8, ShapeText: importer.shapePDFText}
 	var diagnostics []pdfgo.Diagnostic
 	var readWarning func(pdfgo.Diagnostic)
 	if !options.Strict {
@@ -168,11 +173,7 @@ func ImportPDF(ctx context.Context, source io.ReaderAt, size int64, options PDFI
 		return nil, PDFImportReport{}, err
 	}
 	defer reader.Close()
-	editor := NewEditor()
+	importer.reader = reader
-	editor.SetRenderBackends(renderer.Backends())
-	editor.fontDirs, editor.fontFS = renderer.FontSources()
-	editor.fontSourcesCache = renderer.fontSourcesCache
-	importer := pdfImporter{ctx: ctx, reader: reader, editor: editor, renderer: renderer, rasterDPI: renderer.DPI, fontIDs: map[*pdfgo.Font]string{}, fonts: map[*pdfgo.Font]*pdfImportedFont{}, pages: map[pdfgo.Reference]*pdfgo.Page{}, pageIDs: map[pdfgo.Reference]string{}}
 	importer.report.Warnings = diagnostics
 	importer.pageIndexes = make(map[pdfgo.Reference]int)
 	importer.resolveFile = options.ResolveFile

ofdgo_pdf_3d.go

@@ -30,10 +30,16 @@ const pdfModelAttachmentLimit = 1024
 
 // PDFThreeDRenderOptions 控制PDF三维视口的静态绘制，不改变注解激活状态
 // 缓存与实例上限为0时采用U3DRenderOptions的默认值
+// ResolveTexture按原始URL提供外部纹理，空值不访问外部资源
+// Nodes按名称替换PDF视图中的节点状态，可指定动作轨道与采样时间，不改变原始注解
+// Time以秒指定模型动画的采样时刻，零值为初始时刻
 type PDFThreeDRenderOptions struct {
 	Width, Height  int
 	MaxMemoryBytes int64
 	MaxInstances   int
+	ResolveTexture U3DTextureResolver
+	Nodes          []U3DNodeState
+	Time           float64
 }
 
 // threeDAnnotation 按非交互呈现规则处理激活状态，保留原始模型与附件动作
@@ -147,7 +153,13 @@ func (p *pdfImporter) threeDPainter(ctx context.Context, page *pdfgo.Page, sourc
 		if !finite(w) || !finite(h) || w <= 0 || h <= 0 || w > 1<<30 || h > 1<<30 {
 			return nil, fmt.Errorf("invalid PDF 3D raster dimensions")
 		}
-		img, err := RenderPDFThreeD(ctx, model, source, PDFThreeDRenderOptions{Width: int(w), Height: int(h)})
+		options := PDFThreeDRenderOptions{Width: int(w), Height: int(h)}
+		if p.resolveFile != nil {
+			options.ResolveTexture = func(ctx context.Context, address string) ([]byte, error) {
+				return p.resolveFile(ctx, pdfgo.FileSpecification{Name: address, FileSystem: "URL"})
+			}
+		}
+		img, err := RenderPDFThreeD(ctx, model, source, options)
 		if err != nil {
 			return nil, err
 		}
@@ -166,7 +178,7 @@ func (p *pdfImporter) threeDPainter(ctx context.Context, page *pdfgo.Page, sourc
 	}, nil
 }
 
-// RenderPDFThreeD 按PDF相机、投影、背景与灯光绘制3DB区域，不执行脚本或动画
+// RenderPDFThreeD 按PDF相机、投影、背景与灯光绘制指定时刻的3DB区域，不执行脚本
 // 返回图像不含3DB以外的注解背景，未支持的视图效果返回明确错误
 // 每次从传入场景建立独立节点状态，不继承此前绘制的运行时状态
 // 入参: ctx 取消上下文, model 解码后的U3D模型, source PDF三维参数, options 输出与资源限制
@@ -200,7 +212,7 @@ func RenderPDFThreeD(ctx context.Context, model *U3DModel, source pdfgo.ThreeD,
 	if source.Projection != nil {
 		projection = *source.Projection
 	}
-	render := U3DRenderOptions{Width: options.Width, Height: options.Height, MaxMemoryBytes: options.MaxMemoryBytes, MaxInstances: options.MaxInstances, Background: source.Background.RGB}
+	render := U3DRenderOptions{Width: options.Width, Height: options.Height, MaxMemoryBytes: options.MaxMemoryBytes, MaxInstances: options.MaxInstances, Background: source.Background.RGB, ResolveTexture: options.ResolveTexture, Time: options.Time}
 	if err := pdfThreeDRenderMode(source, &render); err != nil {
 		return nil, err
 	}
@@ -210,7 +222,7 @@ func RenderPDFThreeD(ctx context.Context, model *U3DModel, source pdfgo.ThreeD,
 	if err := pdfThreeDSections(ctx, presentation.CrossSections, &render); err != nil {
 		return nil, err
 	}
-	r, err := newU3DRender(ctx, model, render)
+	r, err := newU3DRender(ctx, model, render, options.Nodes)
 	if err != nil {
 		return nil, err
 	}

ofdgo_pdf_font.go

@@ -16,11 +16,10 @@ package ofdgo
 
 import (
 	"bytes"
+	"context"
 	"crypto/sha256"
 	"encoding/binary"
 	"fmt"
-	"maps"
-	"slices"
 	"unicode/utf16"
 	"unicode/utf8"
 
@@ -42,6 +41,46 @@ type pdfFontRepair struct {
 	locations    bool
 }
 
+// shapePDFText 使用导入字体整形注释文字，将毫米坐标约定转换为PDF文字空间方向
+// 入参: ctx 取消上下文, source 源字体, text 单行原文, rightToLeft 段落方向
+// 返回: []pdfgo.ShapedGlyph 千分之一字号的定位字形, error 字体、整形或取消错误
+func (p *pdfImporter) shapePDFText(ctx context.Context, source *pdfgo.Font, text string, rightToLeft bool) ([]pdfgo.ShapedGlyph, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if len(source.Program) == 0 {
+		return nil, &pdfgo.UnsupportedError{Feature: "annotation shaping without embedded font"}
+	}
+	font, err := p.importedFont(source)
+	if err != nil {
+		return nil, err
+	}
+	shaper, ok := font.metrics.(FontShaperOptions)
+	if !ok {
+		return nil, &pdfgo.UnsupportedError{Feature: "annotation text shaping backend"}
+	}
+	options := TextShapeOptions{Bidi: true}
+	if rightToLeft {
+		options.Direction = "rtl"
+	}
+	glyphs, err := shaper.ShapeTextWithOptions(text, 1000, options)
+	if err != nil {
+		return nil, err
+	}
+	result := make([]pdfgo.ShapedGlyph, len(glyphs))
+	units := float64(font.metrics.UnitsPerEm())
+	if units <= 0 {
+		return nil, fmt.Errorf("invalid annotation font units")
+	}
+	for i, glyph := range glyphs {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		result[i] = pdfgo.ShapedGlyph{ID: glyph.Glyph, Cluster: glyph.Cluster, VisualOrder: glyph.VisualOrder, X: glyph.X, Y: -glyph.Y, Advance: glyph.Advance, Width: float64(font.metrics.GlyphAdvance(glyph.Glyph)) * 1000 / units}
+	}
+	return result, ctx.Err()
+}
+
 // embeddedTextFont 匹配同名内嵌字体，仅复用唯一且覆盖全部字符的字形程序
 // 入参: source 外部字体, glyphs 当前文字字形
 // 返回: *pdfImportedFont 可复用字体，无可靠匹配时为空
@@ -292,33 +331,13 @@ func pdfFontProgram(source *pdfgo.Font, type1 *type1Program) ([]byte, pdfFontRep
 		}
 	}
 	if len(tables["cmap"]) == 0 || source.Subtype == "Type0" && invalidCmap || (source.Subtype == "Type0" || source.Subtype == "TrueType") && pdfCmapNeedsRebuild(tables["cmap"]) {
-		mapping := map[rune]uint16{}
+		mapping, err := source.GlyphMap()
-		var codes []string
-		if source.Subtype == "TrueType" {
-			codes = make([]string, 256)
-			for code := range codes {
-				codes[code] = string([]byte{byte(code)})
-			}
-		} else {
-			codes = slices.Sorted(maps.Keys(source.Unicode))
-		}
-		for _, code := range codes {
-			glyphs, err := source.Decode([]byte(code))
 		if err != nil {
 			return nil, repair, err
 		}
-			if len(glyphs) != 1 || !glyphs[0].HasID {
+		for _, glyph := range mapping {
-				return nil, repair, &pdfgo.UnsupportedError{Feature: "font without explicit glyph mapping"}
+			if glyph >= count {
-			}
+				return nil, repair, fmt.Errorf("PDF font glyph %d exceeds glyph count %d", glyph, count)
-			glyph := glyphs[0]
-			if glyph.ID >= count {
-				return nil, repair, fmt.Errorf("PDF font glyph %d exceeds glyph count %d", glyph.ID, count)
-			}
-			if utf8.RuneCountInString(glyph.Text) == 1 {
-				char, _ := utf8.DecodeRuneInString(glyph.Text)
-				if _, exists := mapping[char]; !exists {
-					mapping[char] = glyph.ID
-				}
 			}
 		}
 		addPackedGlyphMapping(mapping, count)

ofdgo_pdf_text_replacement.go

@@ -27,9 +27,11 @@ import (
 type pdfTextReplacement struct {
 	text     *pdfgo.ReplacementText
 	count    int
+	matched  int
 	offset   int64
 	blocked  bool
 	applied  bool
+	identity bool
 }
 
 // pdfTextReplacements 按绘制顺序收集替换区段，避免拆分或重复写入原文
@@ -104,21 +106,26 @@ func (r *pdfTextReplacements) markedContent(mark pdfgo.MarkedContentMark) error
 	return nil
 }
 
-// apply 将完整且样式一致的区段合并为标准OFD文字对象
+// apply 合并可等价表示的替换区段，原文相同但样式不同的区段保留原图元
 // 入参: nodes 原始图元
 // 返回: []pdfCompositeNode 转换图元, error 取消或语义转换错误
 func (r *pdfTextReplacements) apply(nodes []pdfCompositeNode) ([]pdfCompositeNode, error) {
 	if len(r.order) == 0 {
 		return nodes, nil
 	}
-	r.count(nodes, false)
+	if err := r.count(nodes, false); err != nil {
+		return nil, err
+	}
+	for _, span := range r.order {
+		span.identity = !span.blocked && span.count > 0 && span.matched == len(span.text.Text)
+	}
 	var err error
 	nodes, err = r.merge(nodes)
 	if err != nil {
 		return nil, err
 	}
 	for _, span := range r.order {
-		if span.applied || !span.blocked && span.count == 0 && span.text.Text == "" {
+		if span.applied || span.identity || !span.blocked && span.count == 0 && span.text.Text == "" {
 			continue
 		}
 		if r.importer.warning == nil {
@@ -130,14 +137,33 @@ func (r *pdfTextReplacements) apply(nodes []pdfCompositeNode) ([]pdfCompositeNod
 	return nodes, nil
 }
 
-// count 统计完整区段中的文字图元，排除需要组级合成的内容
+// count 统计区段文字并逐字核对原文，排除需要组级合成的内容
 // 入参: nodes 图元, blocked 上层组是否阻止直接转换
-func (r *pdfTextReplacements) count(nodes []pdfCompositeNode, blocked bool) {
+// 返回: error 取消错误
+func (r *pdfTextReplacements) count(nodes []pdfCompositeNode, blocked bool) error {
 	for _, node := range nodes {
+		if err := r.importer.ctx.Err(); err != nil {
+			return err
+		}
 		if node.text != nil {
 			if span := r.span(node.text.Replacement); span != nil {
 				span.count++
 				span.blocked = span.blocked || blocked
+				for i, glyph := range node.text.Glyphs {
+					if span.matched < 0 {
+						break
+					}
+					if i%256 == 0 {
+						if err := r.importer.ctx.Err(); err != nil {
+							return err
+						}
+					}
+					if glyph.Text == "" || !strings.HasPrefix(span.text.Text[span.matched:], glyph.Text) {
+						span.matched = -1
+						break
+					}
+					span.matched += len(glyph.Text)
+				}
 			}
 		}
 		childBlocked := blocked
@@ -145,8 +171,11 @@ func (r *pdfTextReplacements) count(nodes []pdfCompositeNode, blocked bool) {
 			opaque, err := node.opaque(group.ColorSpace)
 			childBlocked = childBlocked || !opaque || err != nil || group.ColorSpace != nil && !group.ColorSpace.SRGBEquivalent()
 		}
-		r.count(node.children, childBlocked)
+		if err := r.count(node.children, childBlocked); err != nil {
+			return err
 		}
+	}
+	return nil
 }
 
 // merge 合并同层连续图元，保留原始绘制顺序与字形坐标
@@ -171,7 +200,7 @@ func (r *pdfTextReplacements) merge(nodes []pdfCompositeNode) ([]pdfCompositeNod
 			first = node.children[0].text
 		}
 		if first != nil {
-			if span := r.span(first.Replacement); span != nil && !span.applied && !span.blocked && span.text.Text != "" {
+			if span := r.span(first.Replacement); span != nil && !span.applied && !span.blocked && span.text.Text != "" && !(span.identity && span.count == 1) {
 				var marks []pdfCompositeNode
 				for end = i; end < len(nodes); end++ {
 					current := nodes[end]
@@ -221,7 +250,7 @@ func (r *pdfTextReplacements) merge(nodes []pdfCompositeNode) ([]pdfCompositeNod
 	return result, nil
 }
 
-// clear 清除未转换的区段引用，防止局部绘制重复使用整段原文
+// clear 清除无需替换及未转换的区段引用，防止局部绘制重复使用整段原文
 // 入参: nodes 图元
 func (r *pdfTextReplacements) clear(nodes []pdfCompositeNode) {
 	for _, node := range nodes {

ofdgo_reader.go

@@ -17,6 +17,7 @@ package ofdgo
 import (
 	"archive/zip"
 	"bytes"
+	"context"
 	"encoding/xml"
 	"fmt"
 	"io"
@@ -546,6 +547,31 @@ func (r *Reader) readFileView(name string) ([]byte, error) {
 	return data, err
 }
 
+// readFileViewContext 读取包内文件并响应取消，已加载数据直接借用
+// 入参: ctx 取消上下文, name 文件名
+// 返回: []byte 只读文件内容, error 读取或取消错误
+func (r *Reader) readFileViewContext(ctx context.Context, name string) ([]byte, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if data, ok := r.files[cleanPackagePath(name)]; ok {
+		return data, nil
+	}
+	input, err := r.openFile(name)
+	if err != nil {
+		return nil, err
+	}
+	defer input.Close()
+	data, err := io.ReadAll(imageInput{ReadCloser: input, context: ctx})
+	if err != nil {
+		return nil, err
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	return data, nil
+}
+
 // readFileData 统一解析包内路径并区分缓存借用与独立读取
 // 入参: name 文件名
 // 返回: []byte 文件内容, bool 是否借用缓存, error 错误信息

ofdgo_u3d.go

@@ -31,7 +31,7 @@ type U3DOptions struct {
 	MaxDecodedBytes int64
 }
 
-// U3DModel 保存独立于PDF的静态U3D场景，不执行动作或读取外部文件
+// U3DModel 保存独立于PDF的U3D场景及动作数据，不执行动作或读取外部文件
 type U3DModel struct {
 	Major, Minor int16
 	DefinedUnits bool
@@ -42,6 +42,8 @@ type U3DModel struct {
 	Shaders      []U3DShader
 	Lights       []U3DLight
 	Views        []U3DViewResource
+	Textures     []U3DTexture
+	Motions      []U3DMotion
 	Metadata     []U3DMetadata
 }
 
@@ -61,6 +63,8 @@ type U3DNode struct {
 	LineShaders          [][]string
 	PointShaders         [][]string
 	View                 *U3DView
+	BoneWeights          []U3DBoneWeights
+	Animations           []U3DAnimation
 }
 
 // U3DParent 保存父节点名称及局部到父节点的变换，空名称引用默认节点
@@ -77,12 +81,13 @@ type U3DMaterial struct {
 	Reflectivity, Opacity                float32
 }
 
-// U3DShader 保存无纹理着色器参数，不提前应用混合、透明测试或光照
+// U3DShader 保存材质与八个纹理通道，Textures中的空项表示未启用
 type U3DShader struct {
 	Name, Material                   string
 	Attributes, AlphaFunction, Blend uint32
 	RenderPass                       uint32
 	AlphaReference                   float32
+	Textures                         [8]*U3DTextureLayer
 }
 
 // U3DLight 保存环境、方向、点或聚光资源，Kind依次为0至3
@@ -110,10 +115,12 @@ type u3dDecoder struct {
 	meshOrder []string
 	nodes     map[string]int
 	palettes  map[uint32]map[string]bool
+	textures  map[string]int
 }
 
-// DecodeU3D 按ECMA-363解码静态基础网格、线集、点集、组、材质、着色器和光源
+// DecodeU3D 按ECMA-363解码静态几何、骨架、场景节点及材质、纹理图像等资源
-// 暂不支持渐进网格、纹理和动画，遇到未支持内容返回错误而非部分场景
+// 保留动作轨道和动画修饰器，不在解码时求值；绘制能力由RenderU3D另行校验
+// 渐进网格尚未支持
 // 点集球面预测暂限不超过两个非对跖方向，不推测多方向合并次序
 // 入参: ctx 取消上下文, data U3D数据, options 解码限制
 // 返回: *U3DModel 独立场景数据, error 格式、能力、预算或取消错误
@@ -177,7 +184,7 @@ func DecodeU3D(ctx context.Context, data []byte, options U3DOptions) (*U3DModel,
 		if err != nil {
 			return nil, fmt.Errorf("U3D block at %d: %w", offset, err)
 		}
-		continuation := block.kind == 0xffffff15 || block.kind == 0xffffff3b || block.kind == 0xffffff3c || block.kind == 0xffffff3e || block.kind == 0xffffff3f
+		continuation := block.kind == 0xffffff15 || block.kind == 0xffffff3b || block.kind == 0xffffff3c || block.kind == 0xffffff3e || block.kind == 0xffffff3f || block.kind == 0xffffff5c
 		if uint64(offset) < declarationEnd && (uint64(end) > declarationEnd || continuation) || uint64(offset) >= declarationEnd && !continuation {
 			return nil, fmt.Errorf("invalid U3D declaration boundary at %d", offset)
 		}
@@ -209,9 +216,15 @@ func DecodeU3D(ctx context.Context, data []byte, options U3DOptions) (*U3DModel,
 		}
 		d.model.Meshes = append(d.model.Meshes, mesh.mesh)
 	}
+	if err := d.checkTextures(); err != nil {
+		return nil, err
+	}
 	if err := d.checkParents(); err != nil {
 		return nil, err
 	}
+	if err := d.checkBoneWeights(); err != nil {
+		return nil, err
+	}
 	if err := ctx.Err(); err != nil {
 		return nil, err
 	}
@@ -307,6 +320,12 @@ func (d *u3dDecoder) chain(block u3dBlock) error {
 	}
 	r := u3dValues{data: block.data}
 	name, kind, flags := r.text(), r.u32(), r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	if name == "" {
+		return fmt.Errorf("cannot redefine U3D default resource")
+	}
 	if kind > 2 || flags & ^uint32(3) != 0 {
 		return fmt.Errorf("invalid U3D modifier chain")
 	}
@@ -367,6 +386,12 @@ func (d *u3dDecoder) block(block u3dBlock, owner string, chain int, index uint32
 	}
 	r := u3dValues{data: block.data}
 	name := r.text()
+	if r.err != nil {
+		return "", r.err
+	}
+	if name == "" {
+		return "", fmt.Errorf("cannot redefine U3D default resource")
+	}
 	var err error
 	switch block.kind {
 	case 0xffffff21, 0xffffff22, 0xffffff23, 0xffffff24:
@@ -394,16 +419,38 @@ func (d *u3dDecoder) block(block u3dBlock, owner string, chain int, index uint32
 			return name, fmt.Errorf("invalid U3D primitive continuation location")
 		}
 		err = d.primitiveContinuation(&r, name, block.kind == 0xffffff3e)
+	case 0xffffff43, 0xffffff44:
+		if (chain != 0 && chain != 1) || index == 0 || owner != name || r.u32() != index {
+			return name, fmt.Errorf("invalid U3D animation or bone weight modifier chain")
+		}
+		if _, exists := d.nodes[name]; chain == 0 && !exists || chain == 1 && d.meshes[name] == nil {
+			return name, fmt.Errorf("missing U3D animation or bone weight modifier target")
+		}
+		if block.kind == 0xffffff43 {
+			err = d.animation(&r, name, chain, index)
+		} else {
+			err = d.boneWeights(&r, name, chain, index)
+		}
 	case 0xffffff45:
 		if chain != 0 || index == 0 || owner != name || r.u32() != index {
 			return name, fmt.Errorf("invalid U3D shading modifier chain")
 		}
 		err = d.shading(&r, name)
-	case 0xffffff51, 0xffffff52, 0xffffff53, 0xffffff54:
+	case 0xffffff51, 0xffffff52, 0xffffff53, 0xffffff54, 0xffffff56:
 		if chain >= 0 {
 			return name, fmt.Errorf("invalid U3D palette resource location")
 		}
 		err = d.resource(&r, block.kind, name)
+	case 0xffffff55:
+		if chain >= 0 && (chain != 2 || index != 0) {
+			return name, fmt.Errorf("invalid U3D texture chain")
+		}
+		err = d.textureDeclaration(&r, name)
+	case 0xffffff5c:
+		if chain >= 0 {
+			return name, fmt.Errorf("invalid U3D texture continuation location")
+		}
+		err = d.textureContinuation(&r, name)
 	default:
 		return name, fmt.Errorf("unsupported U3D block %#x", block.kind)
 	}
@@ -513,7 +560,7 @@ func (d *u3dDecoder) shading(r *u3dValues, name string) error {
 	return r.err
 }
 
-// resource 读取独立材质、着色器、光源和视图资源
+// resource 读取独立材质、着色器、光源、视图和动作资源
 // 入参: r 字段读取器, kind 资源类型, name 资源名
 // 返回: error 结构或能力错误
 func (d *u3dDecoder) resource(r *u3dValues, kind uint32, name string) error {
@@ -527,6 +574,8 @@ func (d *u3dDecoder) resource(r *u3dValues, kind uint32, name string) error {
 	}
 	palette[name] = true
 	switch kind {
+	case 0xffffff56:
+		return d.motion(r, name)
 	case 0xffffff52:
 		return d.viewResource(r, name)
 	case 0xffffff54:
@@ -548,8 +597,28 @@ func (d *u3dDecoder) resource(r *u3dValues, kind uint32, name string) error {
 		if shader.Attributes & ^uint32(7) != 0 || shader.AlphaFunction < 0x610 || shader.AlphaFunction > 0x617 || shader.Blend < 0x604 || shader.Blend > 0x607 || channels & ^uint32(255) != 0 || alpha & ^channels != 0 {
 			return fmt.Errorf("invalid U3D shader parameters")
 		}
-		if channels != 0 {
+		for channel := range shader.Textures {
-			return fmt.Errorf("unsupported U3D textured shader")
+			if channels&(1<<channel) == 0 {
+				continue
+			}
+			if err := d.reserve(1, 192); err != nil {
+				return err
+			}
+			layer := &U3DTextureLayer{Texture: r.text(), Intensity: r.f32(), Blend: r.u8(), BlendSource: r.u8(), BlendConstant: r.f32(), Mode: r.u8(), Alpha: alpha&(1<<channel) != 0}
+			for i := range layer.Transform {
+				layer.Transform[i] = r.f32()
+			}
+			for i := range layer.WrapTransform {
+				layer.WrapTransform[i] = r.f32()
+			}
+			layer.Repeat = r.u8()
+			if r.err != nil {
+				return r.err
+			}
+			if layer.Blend > 3 || layer.BlendSource > 1 || layer.Mode > 4 || layer.Repeat > 3 {
+				return fmt.Errorf("invalid U3D texture layer")
+			}
+			shader.Textures[channel] = layer
 		}
 		d.model.Shaders = append(d.model.Shaders, shader)
 	case 0xffffff51:

ofdgo_u3d_animation.go

@@ -0,0 +1,176 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"context"
+	"fmt"
+	"io"
+)
+
+// U3DAnimation 保存ECMA-363第9.7.3节的动画修饰器，Index为链内位置
+// Attributes的1、2、4、8分别表示启动、锁定根骨骼、单轨播放和动作间平滑过渡
+// TimeScale为整体时间倍率，BlendTime以毫秒计；Motions为空时使用无轨道的默认动作
+type U3DAnimation struct {
+	Index, Attributes    uint32
+	TimeScale, BlendTime float32
+	Motions              []U3DAnimationMotion
+}
+
+// U3DAnimationMotion 保存动画中的动作引用，空名称引用默认动作
+// Attributes的1、2分别表示循环和同步结束，TimeOffset以毫秒计，TimeScale为动作时间倍率
+type U3DAnimationMotion struct {
+	Name                  string
+	Attributes            uint32
+	TimeOffset, TimeScale float32
+}
+
+// animation 读取动画参数及有序动作引用，不在解码时调度或求值
+// 入参: r 字段读取器, name 所属链名, chain 链类型, index 链内位置
+// 返回: error 结构、参数、预算或取消错误
+func (d *u3dDecoder) animation(r *u3dValues, name string, chain int, index uint32) error {
+	animation := U3DAnimation{Index: index, Attributes: r.u32(), TimeScale: r.f32()}
+	count := r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	if len(r.data)-r.pos < 4 || uint64(count) > uint64(len(r.data)-r.pos-4)/14 {
+		return io.ErrUnexpectedEOF
+	}
+	if err := d.reserve(uint64(count), 32); err != nil {
+		return err
+	}
+	if count != 0 {
+		animation.Motions = make([]U3DAnimationMotion, int(count))
+	}
+	for i := range animation.Motions {
+		if i%256 == 0 {
+			if err := d.ctx.Err(); err != nil {
+				return err
+			}
+		}
+		motion := &animation.Motions[i]
+		motion.Name, motion.Attributes = r.text(), r.u32()
+		motion.TimeOffset, motion.TimeScale = r.f32(), r.f32()
+		if r.err != nil {
+			return r.err
+		}
+	}
+	animation.BlendTime = r.f32()
+	if err := r.done(); err != nil {
+		return err
+	}
+	if err := animation.validate(d.ctx); err != nil {
+		return err
+	}
+	if chain == 1 {
+		mesh := &d.meshes[name].mesh
+		mesh.Animations = append(mesh.Animations, animation)
+	} else {
+		node := &d.model.Nodes[d.nodes[name]]
+		node.Animations = append(node.Animations, animation)
+	}
+	return nil
+}
+
+// validate 校验动画属性及有限数值，保留零倍率与反向播放倍率
+// 入参: ctx 取消上下文
+// 返回: error 参数或取消错误
+func (animation U3DAnimation) validate(ctx context.Context) error {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	if animation.Index == 0 || animation.Attributes & ^uint32(15) != 0 || !finite(float64(animation.TimeScale)) || !finite(float64(animation.BlendTime)) || animation.BlendTime < 0 {
+		return fmt.Errorf("invalid U3D animation parameters")
+	}
+	for i, motion := range animation.Motions {
+		if i%256 == 0 {
+			if err := ctx.Err(); err != nil {
+				return err
+			}
+		}
+		if motion.Attributes & ^uint32(3) != 0 || !finite(float64(motion.TimeOffset)) || !finite(float64(motion.TimeScale)) {
+			return fmt.Errorf("invalid U3D animation motion parameters")
+		}
+	}
+	return nil
+}
+
+// checkAnimations 校验全部动作引用，仅对接入场景的修饰器检查求值能力
+// 返回: error 引用、能力或取消错误
+func (r *u3dRender) checkAnimations() error {
+	check := func(animations []U3DAnimation, evaluate bool) error {
+		for _, animation := range animations {
+			if err := animation.validate(r.ctx); err != nil {
+				return err
+			}
+			for i, motion := range animation.Motions {
+				if i%256 == 0 {
+					if err := r.ctx.Err(); err != nil {
+						return err
+					}
+				}
+				if motion.Name == "" {
+					continue
+				}
+				index, exists := r.motionIndex[motion.Name]
+				if !exists {
+					return fmt.Errorf("missing U3D animation motion %q", motion.Name)
+				}
+				if evaluate && len(animation.Motions) > 1 && len(r.model.Motions[index].Tracks) != 0 {
+					return fmt.Errorf("unsupported U3D animation evaluation for motion %q", motion.Name)
+				}
+			}
+		}
+		return nil
+	}
+	var active []bool
+	if r.connected != nil {
+		if err := r.reserve(uint64(len(r.model.Meshes)), 1); err != nil {
+			return err
+		}
+		defer func() { r.remaining += uint64(len(active)) }()
+		active = make([]bool, len(r.model.Meshes))
+		for i, node := range r.model.Nodes {
+			if i%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			if r.connected[i] && node.Kind == "Model" {
+				if mesh, exists := r.meshes[node.Resource]; exists {
+					active[mesh] = true
+				}
+			}
+		}
+	}
+	for i := range r.model.Meshes {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if err := check(r.model.Meshes[i].Animations, active == nil || active[i]); err != nil {
+			return err
+		}
+	}
+	for i := range r.model.Nodes {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if err := check(r.model.Nodes[i].Animations, r.connected == nil || r.connected[i]); err != nil {
+			return err
+		}
+	}
+	return r.ctx.Err()
+}

ofdgo_u3d_bits.go

@@ -46,6 +46,27 @@ type u3dHistogram struct {
 	total  uint32
 }
 
+// finish 校验压缩块的冲刷字段及结束位置
+// 返回: error 截断、冲刷或多余数据错误
+func (r *u3dBits) finish() error {
+	if r.err != nil {
+		return r.err
+	}
+	if r.pos > uint64(len(r.data))*8 {
+		return io.ErrUnexpectedEOF
+	}
+	if r.u32() != 0 {
+		return fmt.Errorf("invalid U3D compression flush")
+	}
+	if r.err != nil {
+		return r.err
+	}
+	if (r.pos-16+7)/8 != uint64(len(r.data)) {
+		return fmt.Errorf("unexpected U3D compressed block data")
+	}
+	return nil
+}
+
 // take 读取定长字段，失败后不继续推进位置
 // 入参: size 字节数
 // 返回: []byte 字段数据，失败时为空

ofdgo_u3d_light.go

@@ -63,10 +63,13 @@ func (r *u3dRender) collectLights() error {
 			continue
 		}
 		j, ok := r.lightIndex[node.Resource]
-		if !ok {
+		if !ok && node.Resource != "" {
 			continue
 		}
-		light := r.model.Lights[j]
+		light := U3DLight{Attributes: 1, Color: [3]float32{.75, .75, .75}}
+		if ok {
+			light = r.model.Lights[j]
+		}
 		if light.Attributes&1 == 0 {
 			continue
 		}
@@ -152,11 +155,21 @@ func (r *u3dRender) overrideLighting(lighting *U3DLighting) error {
 	return nil
 }
 
-// style 解析着色器与材质，未启用的材质项使用固定默认值
+// shaderPass 返回着色器的绘制轮次位图，默认着色器仅参与第一轮
+// 入参: name 着色器名
+// 返回: uint32 绘制轮次位图
+func (r *u3dRender) shaderPass(name string) uint32 {
+	if index, exists := r.shaders[name]; exists {
+		return r.model.Shaders[index].RenderPass
+	}
+	return 1
+}
+
+// style 解析着色器与材质，缺失资源采用ECMA-363第8.4节的默认资源
 // 入参: name 着色器名
 // 返回: u3dRenderStyle 有效绘制参数, error 参数错误
 func (r *u3dRender) style(name string) (u3dRenderStyle, error) {
-	style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, AlphaFunction: 0x617, RenderPass: math.MaxUint32}, ambient: [3]float64{.2, .2, .2}, diffuse: [3]float64{.8, .8, .8}, opacity: 1}
+	style := u3dRenderStyle{shader: U3DShader{Attributes: 1, Blend: 0x606, AlphaFunction: 0x617, RenderPass: 1}, ambient: [3]float64{.75, .75, .75}, opacity: 1}
 	if index, ok := r.shaders[name]; ok {
 		style.shader = r.model.Shaders[index]
 	}
@@ -166,6 +179,7 @@ func (r *u3dRender) style(name string) (u3dRenderStyle, error) {
 	}
 	if index, ok := r.materials[shader.Material]; ok {
 		material := r.model.Materials[index]
+		style.ambient, style.diffuse = [3]float64{.2, .2, .2}, [3]float64{.8, .8, .8}
 		if material.Attributes > 63 {
 			return style, fmt.Errorf("invalid U3D render material")
 		}

ofdgo_u3d_line.go

@@ -68,15 +68,13 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 			if err := r.ctx.Err(); err != nil {
 				return err
 			}
-			style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, RenderPass: math.MaxUint32}}
+			style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, RenderPass: r.shaderPass(name)}}
 			var err error
 			if shaded {
 				style, err = r.style(name)
 				if err != nil {
 					return err
 				}
-			} else if index, ok := r.shaders[name]; ok {
-				style.shader.RenderPass = r.model.Shaders[index].RenderPass
 			}
 			if style.shader.RenderPass&(1<<passIndex) == 0 {
 				continue
@@ -84,15 +82,22 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 			if instance.opacity >= 0 || r.opacity >= 0 {
 				style.shader.Blend = 0x606
 			}
+			textures, err := r.shaderTextures(style.shader)
+			if err != nil {
+				return err
+			}
 			for i, corner := range corners {
+				var normal u3dVector
+				if shaded && !mesh.ExcludeNormals {
+					normal = normals[corner.Normal]
+				}
+				if err := textures.coordinates(&vertices[i], mesh, shading, corner, normal); err != nil {
+					return err
+				}
 				vertices[i].color = [4]float64{r.auxiliaryColor[0], r.auxiliaryColor[1], r.auxiliaryColor[2], 1}
 				if !shaded {
 					continue
 				}
-				var normal u3dVector
-				if !mesh.ExcludeNormals {
-					normal = normals[corner.Normal]
-				}
 				var diffuse, specular *[4]float32
 				if shading.Attributes&1 != 0 {
 					diffuse = &mesh.Diffuse[corner.Diffuse]
@@ -106,8 +111,9 @@ func (r *u3dRender) drawPrimitives(instance u3dInstance, node *U3DNode, mesh *U3
 				}
 				if instance.opacity >= 0 {
 					vertices[i].color[3] = instance.opacity
+					vertices[i].opacityOverride = true
 				}
-				if r.opacity >= 0 {
+				if r.opacity >= 0 && textures == nil {
 					vertices[i].color[3] *= r.opacity
 				}
 			}
@@ -226,7 +232,7 @@ func u3dClipFraction(a, b float64) float64 {
 	return a / (a + b)
 }
 
-// u3dInterpolate 在相机空间插值坐标与未预乘颜色
+// u3dInterpolate 在相机空间插值位置、颜色与纹理输入
 // 入参: a 起点, b 终点, t 比例
 // 返回: u3dVertex 插值顶点
 func u3dInterpolate(a, b u3dVertex, t float64) u3dVertex {
@@ -237,6 +243,18 @@ func u3dInterpolate(a, b u3dVertex, t float64) u3dVertex {
 	for i := range result.color {
 		result.color[i] = a.color[i]*(1-t) + b.color[i]*t
 	}
+	result.textureMask = a.textureMask | b.textureMask
+	result.opacityOverride = a.opacityOverride
+	if result.textureMask != 0 {
+		for layer := range result.texture {
+			if result.textureMask&(1<<layer) == 0 {
+				continue
+			}
+			for c := range result.texture[layer] {
+				result.texture[layer][c] = a.texture[layer][c]*(1-t) + b.texture[layer][c]*t
+			}
+		}
+	}
 	return result
 }
 
@@ -344,6 +362,10 @@ func (r *u3dRender) rasterSectionLine(a, b u3dVertex, rgb [3]float64, normal, or
 // 入参: a 已裁剪起点, b 已裁剪终点, normal 面法线, origin 面上点, shader 着色器, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
 func (r *u3dRender) rasterLine(a, b u3dVertex, normal, origin u3dVector, shader U3DShader, pass U3DViewPass) error {
+	textures, err := r.shaderTextures(shader)
+	if err != nil {
+		return err
+	}
 	cx := r.viewport[0] + r.viewport[2]/2 + r.camera.ShiftX
 	cy := r.viewport[1] + r.viewport[3]/2 + r.camera.ShiftY
 	planes := [4][4]float64{{r.camera.ScaleX, 0, 0, cx}, {-r.camera.ScaleX, 0, 0, float64(r.output.Rect.Dx()) - cx}, {0, -r.camera.ScaleY, 0, cy}, {0, r.camera.ScaleY, 0, float64(r.output.Rect.Dy()) - cy}}
@@ -413,6 +435,9 @@ func (r *u3dRender) rasterLine(a, b u3dVertex, normal, origin u3dVector, shader
 		depth -= 8 * math.Abs(depth-math.Nextafter(depth, math.Inf(-1)))
 		if depth <= r.frame[pixel].depth {
 			vertex := u3dInterpolate(a, b, weight)
+			if err := r.textureColor(textures, &vertex.color, &vertex.texture, vertex.point, vertex.opacityOverride); err != nil {
+				return err
+			}
 			visible, err := u3dFragmentColor(&vertex.color, vertex.point, &shader, &pass)
 			if err != nil {
 				return err

ofdgo_u3d_lineset.go

@@ -16,7 +16,6 @@ package ofdgo
 
 import (
 	"fmt"
-	"io"
 )
 
 // U3D线集增量编码的算术编码上下文
@@ -94,9 +93,11 @@ func (d *u3dDecoder) primitiveDeclaration(r *u3dValues, name string, points bool
 			return fmt.Errorf("invalid U3D reserved primitive parameter")
 		}
 	}
-	if r.u32() != 0 {
+	bones, err := d.skeleton(r)
-		return fmt.Errorf("unsupported U3D skeletal primitive set")
+	if err != nil {
+		return err
 	}
+	decl.mesh.Bones = bones
 	if err := r.done(); err != nil {
 		return err
 	}
@@ -444,17 +445,8 @@ func (d *u3dDecoder) primitiveContinuation(r *u3dValues, name string, points boo
 		}
 	}
 	if b := reader.bits; b != nil {
-		if b.pos > uint64(len(b.data))*8 {
+		if err := b.finish(); err != nil {
-			return io.ErrUnexpectedEOF
+			return err
-		}
-		if b.u32() != 0 {
-			return fmt.Errorf("invalid U3D primitive compression flush")
-		}
-		if b.err != nil {
-			return b.err
-		}
-		if (b.pos-16+7)/8 != uint64(len(b.data)) {
-			return fmt.Errorf("unexpected U3D primitive compressed data")
 		}
 		r.pos = len(r.data)
 	}

ofdgo_u3d_mapping.go

@@ -0,0 +1,141 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"math"
+)
+
+// u3dTextureInverse 计算包裹变换的逆矩阵，保留非仿射齐次分量
+// 入参: matrix 按列排列的包裹变换
+// 返回: [16]float64 逆矩阵, error 奇异矩阵或非有限结果
+func u3dTextureInverse(matrix [16]float32) ([16]float64, error) {
+	var rows [4][8]float64
+	for row := range 4 {
+		for col := range 4 {
+			rows[row][col] = float64(matrix[col*4+row])
+			if !finite(rows[row][col]) {
+				return [16]float64{}, fmt.Errorf("invalid U3D texture wrap transform")
+			}
+		}
+		rows[row][row+4] = 1
+	}
+	for col := range 4 {
+		pivot := col
+		for row := col + 1; row < 4; row++ {
+			if math.Abs(rows[row][col]) > math.Abs(rows[pivot][col]) {
+				pivot = row
+			}
+		}
+		if rows[pivot][col] == 0 {
+			return [16]float64{}, fmt.Errorf("singular U3D texture wrap transform")
+		}
+		rows[col], rows[pivot] = rows[pivot], rows[col]
+		divisor := rows[col][col]
+		for i := range 8 {
+			rows[col][i] /= divisor
+		}
+		for row := range 4 {
+			if row == col {
+				continue
+			}
+			factor := rows[row][col]
+			for i := range 8 {
+				rows[row][i] -= factor * rows[col][i]
+			}
+		}
+	}
+	var result [16]float64
+	for row := range 4 {
+		for col := range 4 {
+			value := rows[row][col+4]
+			if !finite(value) {
+				return [16]float64{}, fmt.Errorf("invalid U3D inverse texture wrap transform")
+			}
+			result[col*4+row] = value
+		}
+	}
+	return result, nil
+}
+
+// generated 将插值后的位置或法线映射到纹理，再应用纹理变换
+// 经线未定义时取0，球心纬度取1/2，反射方向奇点取图像中心
+// 入参: channel 通道索引, input 模型位置或相机法线, position 相机空间位置
+// 返回: [3]float64 齐次纹理坐标, error 非有限值或无效投影
+func (s *u3dTextureSet) generated(channel int, input [3]float64, position u3dVector) ([3]float64, error) {
+	layer := s.layers[channel]
+	for _, value := range input {
+		if !finite(value) {
+			return [3]float64{}, fmt.Errorf("invalid U3D texture mapping input")
+		}
+	}
+	uv := [4]float64{0, 0, 0, 1}
+	if layer.Mode == 4 {
+		incident := u3dVector{0, 0, 1}
+		if s.perspective {
+			incident = position.unit()
+		}
+		normal := u3dVector(input).unit()
+		factor := 2 * normal.dot(incident)
+		reflected := incident.sub(u3dVector{factor * normal[0], factor * normal[1], factor * normal[2]})
+		denominator := 2 * math.Hypot(math.Hypot(reflected[0], reflected[1]), 1-reflected[2])
+		uv[0], uv[1] = .5, .5
+		if denominator != 0 {
+			uv[0] += reflected[0] / denominator
+			uv[1] -= reflected[1] / denominator
+		}
+	} else {
+		var point [4]float64
+		for row := range 4 {
+			point[row] = s.wrap[channel][12+row]
+			for col, value := range input {
+				point[row] += s.wrap[channel][col*4+row] * value
+			}
+		}
+		for i := range 3 {
+			point[i] /= point[3]
+			if !finite(point[i]) {
+				return [3]float64{}, fmt.Errorf("invalid U3D texture wrap projection")
+			}
+		}
+		switch layer.Mode {
+		case 1:
+			uv[0], uv[1] = point[0], point[1]
+		case 2, 3:
+			if point[0] != 0 || point[1] != 0 {
+				uv[0] = math.Atan2(point[1], point[0]) / (2 * math.Pi)
+				if uv[0] < 0 {
+					uv[0]++
+				}
+			}
+			uv[1] = point[2]
+			if layer.Mode == 3 {
+				direction := (u3dVector{point[0], point[1], point[2]}).unit()
+				uv[1] = math.Acos(min(1, max(-1, direction[2]))) / math.Pi
+			}
+		}
+	}
+	var result [3]float64
+	for component, row := range [3]int{0, 1, 3} {
+		for col, value := range uv {
+			result[component] += float64(layer.Transform[col*4+row]) * value
+		}
+		if !finite(result[component]) {
+			return [3]float64{}, fmt.Errorf("invalid U3D generated texture coordinate")
+		}
+	}
+	return result, nil
+}

ofdgo_u3d_mesh.go

@@ -29,6 +29,9 @@ type U3DMesh struct {
 	Faces                                       []U3DFace
 	Lines                                       []U3DLine
 	Points                                      []U3DPoint
+	Bones                                       []U3DBone
+	BoneWeights                                 []U3DBoneWeights
+	Animations                                  []U3DAnimation
 	Quality                                     [3]uint32
 	InverseQuantization                         [5]float32
 	NormalCrease, NormalUpdate, NormalTolerance float32
@@ -76,7 +79,7 @@ type u3dMeshDeclaration struct {
 
 // primitive 访问三角面、线段或点的着色编号和角点，不复制属性数组
 // 入参: index 图元下标，依次为三角面、线段和点
-// 返回: uint32 着色编号, []U3DCorner 只读角点
+// 返回: uint32 着色编号, []U3DCorner 原数组中的角点切片
 func (m *U3DMesh) primitive(index int) (uint32, []U3DCorner) {
 	if index < len(m.Faces) {
 		return m.Faces[index].Shading, m.Faces[index].Corners[:]
@@ -116,16 +119,20 @@ func (d *u3dDecoder) meshDeclaration(r *u3dValues, name string) error {
 		decl.mesh.InverseQuantization[index] = r.f32()
 	}
 	decl.mesh.NormalCrease, decl.mesh.NormalUpdate, decl.mesh.NormalTolerance = r.f32(), r.f32(), r.f32()
-	bones := r.u32()
 	if r.err != nil {
 		return r.err
 	}
 	if minimum > maximum || maximum != decl.counts[1] {
 		return fmt.Errorf("invalid U3D mesh resolution")
 	}
-	if minimum != maximum || bones != 0 {
+	if minimum != maximum {
-		return fmt.Errorf("unsupported U3D progressive or skeletal mesh")
+		return fmt.Errorf("unsupported U3D progressive mesh")
 	}
+	bones, err := d.skeleton(r)
+	if err != nil {
+		return err
+	}
+	decl.mesh.Bones = bones
 	if minimum == 0 {
 		for _, count := range decl.counts[:6] {
 			if count != 0 {
@@ -247,10 +254,16 @@ func (d *u3dDecoder) baseMesh(r *u3dValues, name string) error {
 	var histogram u3dHistogram
 	var compressed *u3dBits
 	if !d.plain && counts[0] != 0 {
-		if err := d.reserve(1, 1<<20); err != nil {
+		compressed = newU3DBits(r.data[r.pos:])
+		var charged uint64
+		compressed.reserve = func(count, size uint64) error {
+			if err := d.reserve(count, size); err != nil {
 				return err
 			}
-		compressed = newU3DBits(r.data[r.pos:])
+			charged += count * size
+			return nil
+		}
+		defer func() { d.remaining += charged }()
 	}
 	readIndex := func(count uint32) (uint32, error) {
 		var value uint32
@@ -321,17 +334,8 @@ func (d *u3dDecoder) baseMesh(r *u3dValues, name string) error {
 		}
 	}
 	if compressed != nil {
-		if compressed.pos > uint64(len(compressed.data))*8 {
+		if err := compressed.finish(); err != nil {
-			return io.ErrUnexpectedEOF
+			return err
-		}
-		if compressed.u32() != 0 {
-			return fmt.Errorf("invalid U3D compression flush")
-		}
-		if compressed.err != nil {
-			return compressed.err
-		}
-		if (compressed.pos-16+7)/8 != uint64(len(compressed.data)) {
-			return fmt.Errorf("unexpected U3D compressed block data: decoded %d bits, stored %d bytes", compressed.pos-16, len(compressed.data))
 		}
 		r.pos = len(r.data)
 	}

ofdgo_u3d_mode.go

@@ -40,12 +40,20 @@ const (
 
 // u3dPrimitiveKey 区分共享点线的颜色及混合状态，避免透明边点重复叠加
 type u3dPrimitiveKey struct {
-	a, b      u3dVertex
+	a, b      [7]float64
 	blend     uint32
 	function  uint32
 	reference float32
 }
 
+// u3dTexturedPrimitiveKey 额外区分纹理坐标及纹理层，不扩大普通边点缓存
+type u3dTexturedPrimitiveKey struct {
+	base            u3dPrimitiveKey
+	coordinates     [2][8][3]float64
+	layers          [8]*U3DTextureLayer
+	opacityOverride bool
+}
+
 // uniquePrimitive 在当前网格内去重着色边点，缓存按条目计入绘制预算
 // 入参: a 起点或顶点, b 终点或相同顶点, shader 着色器
 // 返回: bool 是否首次绘制, error 预算或取消错误
@@ -59,14 +67,29 @@ func (r *u3dRender) uniquePrimitive(a, b u3dVertex, shader U3DShader) (bool, err
 		if left[i] != right[i] {
 			if left[i] > right[i] {
 				a, b = b, a
+				left, right = right, left
 			}
 			break
 		}
 	}
-	key := u3dPrimitiveKey{a: a, b: b, blend: shader.Blend}
+	key := u3dPrimitiveKey{a: left, b: right, blend: shader.Blend}
 	if shader.Attributes&2 != 0 {
 		key.function, key.reference = shader.AlphaFunction, shader.AlphaReference
 	}
+	if shader.Textures != ([8]*U3DTextureLayer{}) {
+		textured := u3dTexturedPrimitiveKey{base: key, coordinates: [2][8][3]float64{a.texture, b.texture}, layers: shader.Textures, opacityOverride: a.opacityOverride}
+		if _, ok := r.texturedPrimitives[textured]; ok {
+			return false, nil
+		}
+		if err := r.reserve(1, 1024); err != nil {
+			return false, err
+		}
+		if r.texturedPrimitives == nil {
+			r.texturedPrimitives = make(map[u3dTexturedPrimitiveKey]struct{})
+		}
+		r.texturedPrimitives[textured] = struct{}{}
+		return true, nil
+	}
 	if _, ok := r.primitives[key]; ok {
 		return false, nil
 	}
@@ -221,6 +244,13 @@ func (r *u3dRender) modePoint(vertex u3dVertex, shader U3DShader, pass U3DViewPa
 	if vertex.point[2] > r.frame[pixel].depth {
 		return nil
 	}
+	textures, err := r.shaderTextures(shader)
+	if err != nil {
+		return err
+	}
+	if err := r.textureColor(textures, &vertex.color, &vertex.texture, vertex.point, vertex.opacityOverride); err != nil {
+		return err
+	}
 	visible, err := u3dFragmentColor(&vertex.color, vertex.point, &shader, &pass)
 	if err != nil || !visible {
 		return err
@@ -251,11 +281,10 @@ func (r *u3dRender) drawBounds(instance u3dInstance, node *U3DNode, mesh *U3DMes
 			}
 		}
 		if uint64(shading) >= uint64(len(shaders)) {
-			visible = true
+			visible = visible || passIndex == 0
 		} else if !visible {
 			for _, name := range shaders[shading] {
-				index, ok := r.shaders[name]
+				if r.shaderPass(name)&(1<<passIndex) != 0 {
-				if !ok || r.model.Shaders[index].RenderPass&(1<<passIndex) != 0 {
 					visible = true
 					break
 				}

ofdgo_u3d_motion.go

@@ -0,0 +1,188 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"math"
+)
+
+// U3DMotion 保存骨骼或节点动作轨道，解码不执行动画
+type U3DMotion struct {
+	Name                                                 string
+	TimeInverseQuantization, RotationInverseQuantization float32
+	Tracks                                               []U3DMotionTrack
+}
+
+// U3DMotionTrack 保存命名轨道及其关键帧，保持文件中的时间与帧次序
+type U3DMotionTrack struct {
+	Name                                                      string
+	DisplacementInverseQuantization, ScaleInverseQuantization float32
+	Frames                                                    []U3DKeyFrame
+}
+
+// U3DKeyFrame 保存关键帧时间及相对父项的变换，Rotation按W、X、Y、Z排列
+type U3DKeyFrame struct {
+	Time                float32
+	Displacement, Scale [3]float32
+	Rotation            [4]float32
+}
+
+// motion 读取ECMA-363第9.8.6节的动作资源，首尾帧保留未量化数值
+// 入参: values 字段读取器, name 资源名
+// 返回: error 结构、数值、预算或取消错误
+func (d *u3dDecoder) motion(values *u3dValues, name string) error {
+	r := u3dResourceReader{values: values, decoder: d}
+	defer r.release()
+	count := r.u32()
+	motion := U3DMotion{Name: name, TimeInverseQuantization: r.f32(), RotationInverseQuantization: r.f32()}
+	if err := r.err(); err != nil {
+		return err
+	}
+	if motion.TimeInverseQuantization < 0 || motion.RotationInverseQuantization < 0 {
+		return fmt.Errorf("invalid U3D motion quantization")
+	}
+	if err := d.reserve(uint64(count), 48); err != nil {
+		return err
+	}
+	motion.Tracks = make([]U3DMotionTrack, int(count))
+	for index := range motion.Tracks {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		track := &motion.Tracks[index]
+		track.Name = r.text()
+		frames := r.u32()
+		track.DisplacementInverseQuantization, track.ScaleInverseQuantization = r.f32(), r.f32()
+		if err := r.err(); err != nil {
+			return err
+		}
+		if track.DisplacementInverseQuantization < 0 || track.ScaleInverseQuantization < 0 {
+			return fmt.Errorf("invalid U3D motion track quantization")
+		}
+		if err := d.reserve(uint64(frames), 44); err != nil {
+			return err
+		}
+		track.Frames = make([]U3DKeyFrame, int(frames))
+		for i := range track.Frames {
+			if i%256 == 0 {
+				if err := d.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			frame := &track.Frames[i]
+			if i == 0 || i == len(track.Frames)-1 {
+				frame.Time = r.f32()
+				for component := range frame.Displacement {
+					frame.Displacement[component] = r.f32()
+				}
+				for component := range frame.Rotation {
+					frame.Rotation[component] = r.f32()
+				}
+				for component := range frame.Scale {
+					frame.Scale[component] = r.f32()
+				}
+			} else if err := r.motionFrame(frame, track.Frames[i-1], &motion, track); err != nil {
+				return err
+			}
+			if err := r.err(); err != nil {
+				return err
+			}
+		}
+	}
+	if err := r.done(); err != nil {
+		return err
+	}
+	d.model.Motions = append(d.model.Motions, motion)
+	return nil
+}
+
+// motionFrame 按前一帧预测时间、位移和缩放，并右乘旋转差分四元数
+// 入参: frame 目标帧, previous 前一帧, motion 动作量化参数, track 轨道量化参数
+// 返回: error 符号、数值或读取错误
+func (r *u3dResourceReader) motionFrame(frame *U3DKeyFrame, previous U3DKeyFrame, motion *U3DMotion, track *U3DMotionTrack) error {
+	time, err := r.motionDifference([]float32{previous.Time}, motion.TimeInverseQuantization, 0)
+	if err != nil {
+		return err
+	}
+	frame.Time = time[0]
+	position, err := r.motionDifference(previous.Displacement[:], track.DisplacementInverseQuantization, 2)
+	if err != nil {
+		return err
+	}
+	copy(frame.Displacement[:], position[:])
+	signs := r.value(4, true)
+	if signs > 15 {
+		return fmt.Errorf("invalid U3D motion rotation signs")
+	}
+	var difference [4]float64
+	var squared float64
+	for component := 1; component < 4; component++ {
+		value := float64(r.value(5, false)) * float64(motion.RotationInverseQuantization)
+		if signs&(1<<component) != 0 {
+			value = -value
+		}
+		difference[component] = value
+		squared += value * value
+	}
+	if err := r.err(); err != nil {
+		return err
+	}
+	if squared > 1 {
+		return fmt.Errorf("invalid U3D motion rotation difference")
+	}
+	difference[0] = math.Sqrt(1 - squared)
+	if signs&1 != 0 {
+		difference[0] = -difference[0]
+	}
+	p := previous.Rotation
+	w, x, y, z := float64(p[0]), float64(p[1]), float64(p[2]), float64(p[3])
+	a, b, c, e := difference[0], difference[1], difference[2], difference[3]
+	frame.Rotation = [4]float32{
+		float32(w*a - x*b - y*c - z*e),
+		float32(w*b + x*a + y*e - z*c),
+		float32(w*c - x*e + y*a + z*b),
+		float32(w*e + x*c - y*b + z*a),
+	}
+	for _, value := range frame.Rotation {
+		if !finite(float64(value)) {
+			return fmt.Errorf("invalid U3D reconstructed rotation")
+		}
+	}
+	scale, err := r.motionDifference(previous.Scale[:], track.ScaleInverseQuantization, 6)
+	copy(frame.Scale[:], scale[:])
+	return err
+}
+
+// motionDifference 用共享幅值上下文恢复一至三个差分分量
+// 入参: previous 前一帧分量, scale 逆量化系数, context 符号上下文，下一项为幅值上下文
+// 返回: [3]float32 重建分量, error 符号、数值或读取错误
+func (r *u3dResourceReader) motionDifference(previous []float32, scale float32, context int) (values [3]float32, err error) {
+	signs := r.value(context, true)
+	if signs >= 1<<len(previous) {
+		return values, fmt.Errorf("invalid U3D motion difference signs")
+	}
+	for index, prior := range previous {
+		difference := float64(r.value(context+1, false)) * float64(scale)
+		if signs&(1<<index) != 0 {
+			difference = -difference
+		}
+		values[index] = float32(float64(prior) + difference)
+		if !finite(float64(values[index])) {
+			return values, fmt.Errorf("invalid U3D reconstructed motion value")
+		}
+	}
+	return values, r.err()
+}

ofdgo_u3d_outline.go

@@ -47,8 +47,7 @@ func (r *u3dRender) outlineFace(outline *u3dOutline, world [3]u3dVector, vertice
 				return err
 			}
 		}
-		index, ok := r.shaders[name]
+		if r.shaderPass(name)&(1<<passIndex) != 0 {
-		if !ok || r.model.Shaders[index].RenderPass&(1<<passIndex) != 0 {
 			active = true
 			break
 		}

ofdgo_u3d_playback.go

@@ -0,0 +1,329 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"cmp"
+	"fmt"
+	"math"
+	"slices"
+)
+
+// u3dAnimationState 保存一次绘制中动画求值的节点变换、骨骼姿态及对应权重
+type u3dAnimationState struct {
+	matrix  u3dMatrix
+	bones   []U3DBoneState
+	weights *U3DBoneWeights
+}
+
+// u3dPlaybackKey 标识一条轨道在指定动作时间的采样，不包含节点绑定
+type u3dPlaybackKey struct {
+	track *U3DMotionTrack
+	time  float64
+}
+
+// u3dPlaybackCache 在一次动画求值中共享轨道时间范围和采样结果
+type u3dPlaybackCache struct {
+	render  *u3dRender
+	bounds  map[*U3DMotionTrack][2]float64
+	samples map[u3dPlaybackKey]U3DKeyFrame
+	bytes   uint64
+}
+
+// limits 校验轨道时间并缓存范围，避免共享动作按节点数量重复扫描全部帧
+// 入参: track 动作轨道
+// 返回: [2]float64 首末时间, error 空轨道、数值、预算或取消错误
+func (c *u3dPlaybackCache) limits(track *U3DMotionTrack) ([2]float64, error) {
+	if err := c.render.ctx.Err(); err != nil {
+		return [2]float64{}, err
+	}
+	if bounds, exists := c.bounds[track]; exists {
+		return bounds, nil
+	}
+	if len(track.Frames) == 0 {
+		return [2]float64{}, fmt.Errorf("empty U3D animation track")
+	}
+	bounds := [2]float64{math.Inf(1), math.Inf(-1)}
+	for i, frame := range track.Frames {
+		if i%256 == 0 {
+			if err := c.render.ctx.Err(); err != nil {
+				return bounds, err
+			}
+		}
+		if !finite(float64(frame.Time)) {
+			return bounds, fmt.Errorf("invalid U3D animation key frame time")
+		}
+		bounds[0], bounds[1] = min(bounds[0], float64(frame.Time)), max(bounds[1], float64(frame.Time))
+	}
+	if c.bounds == nil {
+		if err := c.render.reserve(1, 1024); err != nil {
+			return bounds, err
+		}
+		c.bytes += 1024
+		c.bounds = make(map[*U3DMotionTrack][2]float64)
+	}
+	if err := c.render.reserve(1, 96); err != nil {
+		return bounds, err
+	}
+	c.bytes += 96
+	c.bounds[track] = bounds
+	return bounds, nil
+}
+
+// sample 复用相同轨道和时间的姿态，缓存只在本次求值期间有效
+// 入参: track 动作轨道, time 已换算的动作时间
+// 返回: U3DKeyFrame 采样姿态, error 轨道、预算或取消错误
+func (c *u3dPlaybackCache) sample(track *U3DMotionTrack, time float64) (U3DKeyFrame, error) {
+	if err := c.render.ctx.Err(); err != nil {
+		return U3DKeyFrame{}, err
+	}
+	key := u3dPlaybackKey{track, time}
+	if frame, exists := c.samples[key]; exists {
+		return frame, nil
+	}
+	frame, err := track.Sample(c.render.ctx, time, false)
+	if err != nil {
+		return frame, err
+	}
+	if c.samples == nil {
+		if err := c.render.reserve(1, 1024); err != nil {
+			return frame, err
+		}
+		c.bytes += 1024
+		c.samples = make(map[u3dPlaybackKey]U3DKeyFrame)
+	}
+	if err := c.render.reserve(1, 128); err != nil {
+		return frame, err
+	}
+	c.bytes += 128
+	c.samples[key] = frame
+	return frame, nil
+}
+
+// prepareAnimations 按资源链、节点链顺序求值，不保存上一帧状态或推进实际时钟
+// 入参: time 从初始时刻起算的秒数
+// 返回: error 动作、骨架、修饰顺序、预算或取消错误
+func (r *u3dRender) prepareAnimations(time float64) error {
+	cache := u3dPlaybackCache{render: r}
+	defer func() { r.remaining += cache.bytes }()
+	for i := range r.model.Nodes {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if r.connected != nil && !r.connected[i] {
+			continue
+		}
+		node := &r.model.Nodes[i]
+		mesh := r.nodeMesh(node)
+		groups := [2][]U3DAnimation{nil, node.Animations}
+		if node.Kind == "Model" && mesh != nil {
+			groups[0] = mesh.Animations
+		}
+		state := u3dAnimationState{matrix: u3dIdentity()}
+		used := false
+		for chain, group := range groups {
+			ordered := group
+			if len(group) > 1 {
+				if err := r.reserve(uint64(len(group)), 48); err != nil {
+					return err
+				}
+				ordered = slices.Clone(group)
+				slices.SortFunc(ordered, func(a, b U3DAnimation) int { return cmp.Compare(a.Index, b.Index) })
+			}
+			for index, animation := range ordered {
+				if err := r.ctx.Err(); err != nil {
+					return err
+				}
+				if index != 0 && animation.Index == ordered[index-1].Index {
+					return fmt.Errorf("duplicate U3D animation chain index")
+				}
+				if len(animation.Motions) == 0 || animation.Motions[0].Name == "" {
+					continue
+				}
+				motion := &r.model.Motions[r.motionIndex[animation.Motions[0].Name]]
+				if len(motion.Tracks) == 0 {
+					continue
+				}
+				used = true
+				if err := r.sampleAnimation(&state, node, mesh, &animation, motion, chain, time, &cache); err != nil {
+					return err
+				}
+			}
+			if len(group) > 1 {
+				r.remaining += uint64(len(group)) * 48
+			}
+		}
+		if used {
+			if r.animated == nil {
+				if err := r.reserve(1, 1024); err != nil {
+					return err
+				}
+				r.animated = make(map[string]u3dAnimationState)
+			}
+			if err := r.reserve(1, 384); err != nil {
+				return err
+			}
+			r.animated[node.Name] = state
+		}
+	}
+	return r.ctx.Err()
+}
+
+// animationTime 将毫秒偏移和两级时间倍率换算为动作时间，已绑定轨道共用循环区间
+// 入参: animation 动画修饰器, tracks 动作轨道, bindings 骨骼绑定，空值表示全部轨道, time 从初始时刻起算的秒数, cache 本次采样缓存
+// 返回: float64 动作采样时间, error 时间数值或取消错误
+func (r *u3dRender) animationTime(animation *U3DAnimation, tracks []U3DMotionTrack, bindings map[string]int, time float64, cache *u3dPlaybackCache) (float64, error) {
+	reference := animation.Motions[0]
+	if animation.Attributes&1 == 0 {
+		time = 0
+	}
+	time = time*float64(animation.TimeScale)*float64(reference.TimeScale) - float64(reference.TimeOffset)/1000
+	if !finite(time) {
+		return 0, fmt.Errorf("invalid U3D animation time")
+	}
+	minimum, maximum := math.Inf(1), math.Inf(-1)
+	for i, track := range tracks {
+		if err := r.ctx.Err(); err != nil {
+			return 0, err
+		}
+		if bindings != nil {
+			if index, exists := bindings[track.Name]; !exists || index != i {
+				continue
+			}
+		}
+		bounds, err := cache.limits(&tracks[i])
+		if err != nil {
+			return 0, err
+		}
+		minimum, maximum = min(minimum, bounds[0]), max(maximum, bounds[1])
+	}
+	if math.IsInf(minimum, 1) {
+		return 0, fmt.Errorf("empty U3D animation tracks")
+	}
+	if reference.Attributes&1 != 0 && maximum > minimum {
+		time = math.Mod(time-minimum, maximum-minimum)
+		if time < 0 {
+			time += maximum - minimum
+		}
+		time += minimum
+	}
+	return max(minimum, min(time, maximum)), r.ctx.Err()
+}
+
+// sampleAnimation 求值单个动作的节点或骨骼姿态，锁定根骨骼时保留其初始变换
+// 入参: state 本节点累计状态, node 节点, mesh 模型几何, animation 修饰器, motion 动作, chain 链类别, time 时间, cache 本次采样缓存
+// 返回: error 轨道、修饰顺序、预算或取消错误
+func (r *u3dRender) sampleAnimation(state *u3dAnimationState, node *U3DNode, mesh *U3DMesh, animation *U3DAnimation, motion *U3DMotion, chain int, time float64, cache *u3dPlaybackCache) error {
+	if animation.Attributes&4 != 0 {
+		if chain == 0 {
+			return fmt.Errorf("unsupported U3D resource single-track animation")
+		}
+		time, err := r.animationTime(animation, motion.Tracks[:1], nil, time, cache)
+		if err != nil {
+			return err
+		}
+		frame, err := cache.sample(&motion.Tracks[0], time)
+		if err != nil {
+			return err
+		}
+		matrix, err := frame.Matrix()
+		if err != nil {
+			return err
+		}
+		if animation.Attributes&2 == 0 {
+			state.matrix = state.matrix.multiply(u3dMatrix(matrix))
+			if !state.matrix.valid() {
+				return fmt.Errorf("invalid U3D animated node transform")
+			}
+		}
+		return nil
+	}
+	if node.Kind != "Model" || mesh == nil || len(mesh.Bones) == 0 {
+		return fmt.Errorf("missing U3D animation skeleton")
+	}
+	if state.weights != nil {
+		return fmt.Errorf("unsupported U3D successive skeletal animations")
+	}
+	if err := r.reserve(uint64(len(mesh.Bones)), 96); err != nil {
+		return err
+	}
+	defer func() { r.remaining += uint64(len(mesh.Bones)) * 96 }()
+	tracks := make(map[string]int, len(mesh.Bones))
+	for i, bone := range mesh.Bones {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return err
+			}
+		}
+		if _, exists := tracks[bone.Name]; exists {
+			return fmt.Errorf("duplicate U3D bone %q", bone.Name)
+		}
+		tracks[bone.Name] = -1
+	}
+	bound := 0
+	for i, track := range motion.Tracks {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return err
+			}
+		}
+		if index, exists := tracks[track.Name]; exists {
+			if index >= 0 {
+				return fmt.Errorf("ambiguous U3D animation track %q", track.Name)
+			}
+			tracks[track.Name] = i
+			bound++
+		}
+	}
+	if bound == 0 {
+		return nil
+	}
+	time, err := r.animationTime(animation, motion.Tracks, tracks, time, cache)
+	if err != nil {
+		return err
+	}
+	if err := r.reserve(uint64(len(mesh.Bones)), 64); err != nil {
+		return err
+	}
+	state.bones = make([]U3DBoneState, 0, len(mesh.Bones))
+	for i, bone := range mesh.Bones {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return err
+			}
+		}
+		if i == 0 && animation.Attributes&2 != 0 {
+			continue
+		}
+		if index := tracks[bone.Name]; index >= 0 {
+			frame, err := cache.sample(&motion.Tracks[index], time)
+			if err != nil {
+				return err
+			}
+			state.bones = append(state.bones, U3DBoneState{Name: bone.Name, Frame: frame})
+		}
+	}
+	if len(state.bones) == 0 {
+		r.remaining += uint64(cap(state.bones)) * 64
+		state.bones = nil
+		return nil
+	}
+	resourceEnd, nodeEnd := uint64(animation.Index), uint64(0)
+	if chain != 0 {
+		resourceEnd, nodeEnd = math.MaxUint64, uint64(animation.Index)
+	}
+	state.weights, err = r.skinWeightSet(mesh, node.BoneWeights, resourceEnd, nodeEnd)
+	return err
+}

ofdgo_u3d_render.go

@@ -36,9 +36,12 @@ type U3DCamera struct {
 // Camera为空时使用View指定的节点或首个视图节点，Instance指定其父路径实例
 // Lighting为空时沿用模型灯光，非空时替换全部模型灯光
 // Opacity为空时沿用着色器混合，非空时叠加面片、着色边点及包围盒轮廓的透明度
+// 纹理合成后先应用节点透明度，再应用Opacity
 // Mode控制绘制方式，AuxiliaryColor用于固定颜色的边点，FaceColor用于包围盒面及插图面，空值分别使用黑色和背景色
 // CreaseAngle为轮廓夹角，单位为度，空值使用45；着色插图以漫反射色的1/4补充自发光
 // Nodes按名称覆盖节点，重复名称使用最后一项，每次绘制均从原场景开始
+// Time以秒指定动画采样时刻，零值为初始时刻，不随实际时钟推进
+// ResolveTexture提供外部纹理，空值不访问外部资源；回调自身的内存与超时由调用方控制
 // Background为空时使用白色；缓存与实例上限为0时分别使用256MiB和65536，不含输入及运行时开销
 type U3DRenderOptions struct {
 	Width, Height  int
@@ -53,7 +56,9 @@ type U3DRenderOptions struct {
 	FaceColor      *[3]float64
 	CreaseAngle    *float64
 	Nodes          []U3DNodeState
+	Time           float64
 	Sections       []U3DCrossSection
+	ResolveTexture U3DTextureResolver
 	MaxMemoryBytes int64
 	MaxInstances   int
 }
@@ -87,8 +92,15 @@ type u3dRender struct {
 	toCamera                               u3dMatrix
 	scene                                  []u3dInstance
 	byNode                                 [][]int
+	connected                              []bool
 	members                                []bool
 	meshes, shaders, materials, lightIndex map[string]int
+	textureIndex                           map[string]int
+	viewIndex, motionIndex                 map[string]int
+	textures                               map[string]*image.NRGBA64
+	textureSets                            map[[8]*U3DTextureLayer]*u3dTextureSet
+	resolveTexture                         U3DTextureResolver
+	view                                   *U3DView
 	lights                                 []u3dRenderLight
 	lighting                               *U3DLighting
 	opacity                                float64
@@ -97,7 +109,10 @@ type u3dRender struct {
 	auxiliaryColor, faceColor              [3]float64
 	depthOnly                              bool
 	primitives                             map[u3dPrimitiveKey]struct{}
+	texturedPrimitives                     map[u3dTexturedPrimitiveKey]struct{}
 	states                                 map[string]U3DNodeState
+	posed                                  map[string]*U3DMesh
+	animated                               map[string]u3dAnimationState
 	sections                               []u3dSection
 	sectionScratch                         [2][]u3dVertex
 	chunks                                 [][]u3dFragment
@@ -106,8 +121,16 @@ type u3dRender struct {
 	order                                  uint64
 }
 
-// RenderU3D 绘制静态无纹理网格、线集、点集及包围盒，返回不透明图像，不执行脚本或动画
+// RenderU3D 绘制几何及视图纹理层，返回指定时刻的不透明图像，不执行脚本
-// 采用逐顶点光照及逐像素深度混合，缺失资源回退为空网格、灰色材质或无光源
+// 可通过节点覆盖指定动作轨道与采样时间，逐次生成独立姿态，不修改原模型
+// 显式骨骼姿态按权重变换位置和法线，暂不生成骨骼链接或推导缺失权重
+// 动画修饰器支持单动作的节点和骨骼求值，尚未实现的动作衔接返回明确错误
+// 几何纹理支持模型坐标与程序化映射，参考形状约定见U3DTextureLayer
+// 纹理按需解码并复用，不自动访问外部图像
+// 采用逐顶点光照及逐像素深度混合，空名称引用标准默认资源
+// 缺失几何、材质和着色器采用默认资源，缺失的非空光源引用不产生光照
+// 缺失纹理返回错误，空纹理名称使用标准默认图像
+// 仅绘制默认根的后代，非空父节点引用缺失时不展开该父路径
 // 入参: ctx 取消上下文, model 场景, options 视图、输出与资源限制
 // 返回: *image.RGBA 图像, error 参数、能力、预算或取消错误
 func RenderU3D(ctx context.Context, model *U3DModel, options U3DRenderOptions) (*image.RGBA, error) {
@@ -123,17 +146,17 @@ func RenderU3D(ctx context.Context, model *U3DModel, options U3DRenderOptions) (
 }
 
 // newU3DRender 建立有预算限制的场景实例与资源索引
-// 入参: ctx 取消上下文, model 场景, options 输出与资源限制
+// 入参: ctx 取消上下文, model 场景, options 输出与资源限制, states 后续节点覆盖分组
 // 返回: *u3dRender 绘制状态, error 参数、场景、预算或取消错误
-func newU3DRender(ctx context.Context, model *U3DModel, options U3DRenderOptions) (*u3dRender, error) {
+func newU3DRender(ctx context.Context, model *U3DModel, options U3DRenderOptions, states ...[]U3DNodeState) (*u3dRender, error) {
-	if ctx == nil || model == nil || options.Width <= 0 || options.Height <= 0 || options.MaxMemoryBytes < 0 || options.MaxInstances < 0 || options.Instance < 0 {
+	if ctx == nil || model == nil || options.Width <= 0 || options.Height <= 0 || options.MaxMemoryBytes < 0 || options.MaxInstances < 0 || options.Instance < 0 || !finite(options.Time) {
 		return nil, fmt.Errorf("invalid U3D render options")
 	}
 	limit := options.MaxMemoryBytes
 	if limit == 0 {
 		limit = u3dDefaultBytes
 	}
-	r := &u3dRender{ctx: ctx, model: model, remaining: uint64(limit), opacity: -1, mode: options.Mode, creaseAngle: 45}
+	r := &u3dRender{ctx: ctx, model: model, remaining: uint64(limit), opacity: -1, mode: options.Mode, creaseAngle: 45, resolveTexture: options.ResolveTexture}
 	if options.Mode > U3DRenderShadedIllustration {
 		return nil, fmt.Errorf("unsupported U3D render mode")
 	}
@@ -157,23 +180,37 @@ func newU3DRender(ctx context.Context, model *U3DModel, options U3DRenderOptions
 	if err := r.reserve(pixels, 60); err != nil {
 		return nil, err
 	}
+	if err := r.resources(); err != nil {
+		return nil, err
+	}
+	order, index, err := r.sceneGraph()
+	if err != nil {
+		return nil, err
+	}
+	if err := r.checkAnimations(); err != nil {
+		return nil, err
+	}
 	maxInstances := options.MaxInstances
 	if maxInstances == 0 {
 		maxInstances = 65536
 	}
-	if err := r.nodeStates(options.Nodes); err != nil {
+	groups := append([][]U3DNodeState{options.Nodes}, states...)
+	if err := r.nodeStates(groups...); err != nil {
 		return nil, err
 	}
-	if err := r.instances(maxInstances); err != nil {
+	if err := r.prepareAnimations(options.Time); err != nil {
+		return nil, err
+	}
+	if err := r.instances(order, index, maxInstances); err != nil {
+		return nil, err
+	}
+	if err := r.poseNodes(); err != nil {
 		return nil, err
 	}
 	if err := r.reserve(uint64(len(r.scene)), 1); err != nil {
 		return nil, err
 	}
 	r.members = make([]bool, len(r.scene))
-	if err := r.resources(); err != nil {
-		return nil, err
-	}
 	return r, nil
 }
 
@@ -223,11 +260,21 @@ func (r *u3dRender) render(options U3DRenderOptions, passes []U3DViewPass) (*ima
 		}
 		r.frame[i].color = background
 	}
+	if r.view != nil {
+		if err := r.viewLayers(r.view.Backdrops); err != nil {
+			return nil, err
+		}
+	}
 	for passIndex, pass := range passes {
 		if err := r.renderPass(pass, passIndex, passIndex == len(passes)-1); err != nil {
 			return nil, err
 		}
 	}
+	if r.view != nil {
+		if err := r.viewLayers(r.view.Overlays); err != nil {
+			return nil, err
+		}
+	}
 	for i, pixel := range r.frame {
 		if i%4096 == 0 {
 			if err := r.ctx.Err(); err != nil {
@@ -263,6 +310,7 @@ func (r *u3dRender) reserve(count, size uint64) error {
 // 入参: options 绘制选项
 // 返回: []U3DViewPass 绘制轮次, error 视图或投影错误
 func (r *u3dRender) selectView(options U3DRenderOptions) ([]U3DViewPass, error) {
+	r.view = nil
 	r.viewport = [4]float64{0, 0, float64(options.Width), float64(options.Height)}
 	selected := -1
 	for i, node := range r.model.Nodes {
@@ -286,23 +334,12 @@ func (r *u3dRender) selectView(options U3DRenderOptions) ([]U3DViewPass, error)
 			return nil, fmt.Errorf("invalid U3D view node")
 		}
 		view := node.View
-		if len(view.Backdrops) != 0 || len(view.Overlays) != 0 {
+		if view.Attributes & ^uint32(7) != 0 {
-			return nil, fmt.Errorf("unsupported U3D textured view layers")
+			return nil, fmt.Errorf("invalid U3D view attributes")
-		}
-		found := false
-		for i, resource := range r.model.Views {
-			if i%256 == 0 {
-				if err := r.ctx.Err(); err != nil {
-					return nil, err
-				}
-			}
-			if resource.Name == node.Resource {
-				if found {
-					return nil, fmt.Errorf("duplicate U3D view resource")
-				}
-				passes = resource.Passes
-				found = true
 		}
+		r.view = view
+		if i, exists := r.viewIndex[node.Resource]; exists {
+			passes = r.model.Views[i].Passes
 		}
 		if options.Camera == nil {
 			if options.Instance >= len(r.byNode[selected]) {
@@ -374,10 +411,10 @@ func (r *u3dRender) selectView(options U3DRenderOptions) ([]U3DViewPass, error)
 	return passes, nil
 }
 
-// resources 建立只读资源索引，不按名称反复扫描场景
+// resources 建立只读资源索引，空名称保留给标准默认资源
-// 返回: error 重名或预算错误
+// 返回: error 名称、预算或取消错误
 func (r *u3dRender) resources() error {
-	count := uint64(len(r.model.Meshes)) + uint64(len(r.model.Shaders)) + uint64(len(r.model.Materials)) + uint64(len(r.model.Lights))
+	count := uint64(len(r.model.Meshes)) + uint64(len(r.model.Shaders)) + uint64(len(r.model.Materials)) + uint64(len(r.model.Lights)) + uint64(len(r.model.Textures)) + uint64(len(r.model.Views)) + uint64(len(r.model.Motions))
 	if err := r.reserve(count, 96); err != nil {
 		return err
 	}
@@ -385,12 +422,18 @@ func (r *u3dRender) resources() error {
 	r.shaders = make(map[string]int, len(r.model.Shaders))
 	r.materials = make(map[string]int, len(r.model.Materials))
 	r.lightIndex = make(map[string]int, len(r.model.Lights))
+	r.textureIndex = make(map[string]int, len(r.model.Textures))
+	r.viewIndex = make(map[string]int, len(r.model.Views))
+	r.motionIndex = make(map[string]int, len(r.model.Motions))
 	add := func(index map[string]int, name string, i int) error {
 		if i%256 == 0 {
 			if err := r.ctx.Err(); err != nil {
 				return err
 			}
 		}
+		if name == "" {
+			return fmt.Errorf("cannot redefine U3D default resource")
+		}
 		if _, ok := index[name]; ok {
 			return fmt.Errorf("duplicate U3D render resource %q", name)
 		}
@@ -417,6 +460,21 @@ func (r *u3dRender) resources() error {
 			return err
 		}
 	}
+	for i, v := range r.model.Textures {
+		if err := add(r.textureIndex, v.Name, i); err != nil {
+			return err
+		}
+	}
+	for i, v := range r.model.Views {
+		if err := add(r.viewIndex, v.Name, i); err != nil {
+			return err
+		}
+	}
+	for i, v := range r.model.Motions {
+		if err := add(r.motionIndex, v.Name, i); err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
@@ -494,11 +552,11 @@ func (r *u3dRender) drawScene(pass U3DViewPass, passIndex int) error {
 		if node.Visibility > 3 {
 			return fmt.Errorf("invalid U3D model visibility")
 		}
-		mesh, ok := r.meshes[node.Resource]
+		mesh := r.nodeMesh(node)
-		if !ok {
+		if mesh == nil {
 			continue
 		}
-		if err := r.drawMesh(instance, node, &r.model.Meshes[mesh], pass, passIndex); err != nil {
+		if err := r.drawMesh(instance, node, mesh, pass, passIndex); err != nil {
 			return err
 		}
 	}

ofdgo_u3d_resource_reader.go

@@ -0,0 +1,141 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"math"
+	"unicode/utf8"
+)
+
+// u3dResourceReader 读取骨骼权重与动作资源中交错的普通字段和压缩字段
+type u3dResourceReader struct {
+	values  *u3dValues
+	decoder *u3dDecoder
+	bits    *u3dBits
+	hist    [8]u3dHistogram
+	charged uint64
+}
+
+// value 读取指定上下文的压缩字段，首次使用时初始化算术区间
+// 入参: context 压缩上下文, small 是否为8位字段
+// 返回: uint32 字段值
+func (r *u3dResourceReader) value(context int, small bool) uint32 {
+	if r.err() != nil {
+		return 0
+	}
+	if r.decoder.plain {
+		if small {
+			return uint32(r.values.u8())
+		}
+		return r.values.u32()
+	}
+	if r.bits == nil {
+		r.bits = newU3DBits(r.values.data[r.values.pos:])
+		r.bits.reserve = func(count, size uint64) error {
+			if err := r.decoder.reserve(count, size); err != nil {
+				return err
+			}
+			r.charged += count * size
+			return nil
+		}
+	}
+	return r.bits.dynamicValue(&r.hist[context], small)
+}
+
+// u32 读取普通32位字段，压缩开始后沿用当前算术区间
+// 返回: uint32 字段值
+func (r *u3dResourceReader) u32() uint32 {
+	if r.bits != nil {
+		return r.bits.u32()
+	}
+	return r.values.u32()
+}
+
+// f32 读取有限单精度数值
+// 返回: float32 字段值
+func (r *u3dResourceReader) f32() float32 {
+	value := math.Float32frombits(r.u32())
+	if !finite(float64(value)) && r.err() == nil {
+		r.values.err = fmt.Errorf("invalid U3D floating-point value")
+	}
+	return value
+}
+
+// text 读取UTF-8名称，压缩开始后逐字节解码而不重置区间
+// 返回: string 名称
+func (r *u3dResourceReader) text() string {
+	if r.err() != nil {
+		return ""
+	}
+	if r.bits == nil {
+		return r.values.text()
+	}
+	length := int(r.bits.byteValue()) | int(r.bits.byteValue())<<8
+	if r.err() != nil {
+		return ""
+	}
+	if err := r.decoder.reserve(uint64(length), 2); err != nil {
+		r.values.err = err
+		return ""
+	}
+	data := make([]byte, length)
+	for index := range data {
+		if index%1024 == 0 {
+			if err := r.decoder.ctx.Err(); err != nil {
+				r.values.err = err
+				return ""
+			}
+		}
+		data[index] = r.bits.byteValue()
+	}
+	if r.err() == nil && !utf8.Valid(data) {
+		r.values.err = fmt.Errorf("invalid U3D UTF-8 string")
+	}
+	return string(data)
+}
+
+// err 返回字段或算术解码错误
+// 返回: error 读取错误
+func (r *u3dResourceReader) err() error {
+	if r.values.err != nil {
+		return r.values.err
+	}
+	if r.bits != nil {
+		return r.bits.err
+	}
+	return nil
+}
+
+// done 校验末尾冲刷字段和块边界
+// 返回: error 读取或多余数据错误
+func (r *u3dResourceReader) done() error {
+	if err := r.err(); err != nil {
+		return err
+	}
+	if r.bits != nil {
+		if err := r.bits.finish(); err != nil {
+			return err
+		}
+		r.values.pos = len(r.values.data)
+	}
+	return r.values.done()
+}
+
+// release 归还当前块压缩上下文占用的临时预算
+func (r *u3dResourceReader) release() {
+	r.decoder.remaining += r.charged
+	r.charged = 0
+}

ofdgo_u3d_sample.go

@@ -0,0 +1,215 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"context"
+	"fmt"
+	"math"
+)
+
+// U3DTrackState 指定动作资源、轨道和采样时间，Time与关键帧使用相同单位
+// Loop将时间循环到首末帧之间，未启用时停留在端点，不自动解释动画修饰器的时间参数
+type U3DTrackState struct {
+	Motion, Track string
+	Time          float64
+	Loop          bool
+}
+
+// Sample 按时间采样轨道，不修改原始帧或按帧数量分配临时数组
+// 位移和缩放采用线性插值，旋转归一化后采用最短弧球面插值
+// 允许帧乱序，同一时刻取文件中最后一帧；循环区间不包含末端，单帧轨道始终返回该帧
+// 入参: ctx 取消上下文, time 与关键帧同单位的时间, loop 是否循环
+// 返回: U3DKeyFrame 采样姿态, error 空轨道、数值或取消错误
+func (track U3DMotionTrack) Sample(ctx context.Context, time float64, loop bool) (U3DKeyFrame, error) {
+	if ctx == nil || !finite(time) || len(track.Frames) == 0 {
+		return U3DKeyFrame{}, fmt.Errorf("invalid U3D motion sample")
+	}
+	first, last := 0, 0
+	for index, frame := range track.Frames {
+		if index%256 == 0 {
+			if err := ctx.Err(); err != nil {
+				return U3DKeyFrame{}, err
+			}
+		}
+		if !finite(float64(frame.Time)) {
+			return U3DKeyFrame{}, fmt.Errorf("invalid U3D key frame time")
+		}
+		if frame.Time <= track.Frames[first].Time {
+			first = index
+		}
+		if frame.Time >= track.Frames[last].Time {
+			last = index
+		}
+	}
+	minimum, maximum := float64(track.Frames[first].Time), float64(track.Frames[last].Time)
+	if loop && maximum > minimum {
+		time = math.Mod(time-minimum, maximum-minimum)
+		if time < 0 {
+			time += maximum - minimum
+		}
+		time += minimum
+	} else {
+		time = max(minimum, min(time, maximum))
+	}
+	lower, upper := first, last
+	for index, frame := range track.Frames {
+		if index%256 == 0 {
+			if err := ctx.Err(); err != nil {
+				return U3DKeyFrame{}, err
+			}
+		}
+		value := float64(frame.Time)
+		if value <= time && frame.Time >= track.Frames[lower].Time {
+			lower = index
+		}
+		if value > time && frame.Time <= track.Frames[upper].Time {
+			upper = index
+		}
+	}
+	a, b := track.Frames[lower], track.Frames[upper]
+	if float64(a.Time) == time {
+		b = a
+	}
+	qa, err := a.quaternion()
+	if err != nil {
+		return U3DKeyFrame{}, err
+	}
+	qb, err := b.quaternion()
+	if err != nil {
+		return U3DKeyFrame{}, err
+	}
+	fraction := float64(0)
+	if b.Time != a.Time {
+		fraction = (time - float64(a.Time)) / (float64(b.Time) - float64(a.Time))
+	}
+	result := U3DKeyFrame{Time: float32(time)}
+	for i := range result.Displacement {
+		result.Displacement[i] = float32(float64(a.Displacement[i])*(1-fraction) + float64(b.Displacement[i])*fraction)
+		result.Scale[i] = float32(float64(a.Scale[i])*(1-fraction) + float64(b.Scale[i])*fraction)
+	}
+	var dot float64
+	for i := range qa {
+		dot += qa[i] * qb[i]
+	}
+	if dot < 0 {
+		dot = -dot
+		for i := range qb {
+			qb[i] = -qb[i]
+		}
+	}
+	left, right := 1-fraction, fraction
+	if dot < .9995 {
+		angle := math.Acos(min(1, dot))
+		divisor := math.Sin(angle)
+		left, right = math.Sin(left*angle)/divisor, math.Sin(right*angle)/divisor
+	}
+	var rotation [4]float64
+	var length float64
+	for i := range rotation {
+		rotation[i] = left*qa[i] + right*qb[i]
+		length += rotation[i] * rotation[i]
+	}
+	length = math.Sqrt(length)
+	for i := range result.Rotation {
+		result.Rotation[i] = float32(rotation[i] / length)
+	}
+	if err := ctx.Err(); err != nil {
+		return U3DKeyFrame{}, err
+	}
+	return result, nil
+}
+
+// quaternion 校验姿态分量并归一化W、X、Y、Z旋转四元数
+// 返回: [4]float64 单位四元数, error 非有限或零旋转错误
+func (frame U3DKeyFrame) quaternion() ([4]float64, error) {
+	var rotation [4]float64
+	for _, values := range [][3]float32{frame.Displacement, frame.Scale} {
+		for _, value := range values {
+			if !finite(float64(value)) {
+				return rotation, fmt.Errorf("invalid U3D key frame transform")
+			}
+		}
+	}
+	var length float64
+	for i, value := range frame.Rotation {
+		rotation[i] = float64(value)
+		length += rotation[i] * rotation[i]
+	}
+	if !finite(length) || length == 0 {
+		return rotation, fmt.Errorf("invalid U3D key frame rotation")
+	}
+	length = math.Sqrt(length)
+	for i := range rotation {
+		rotation[i] /= length
+	}
+	return rotation, nil
+}
+
+// Matrix 将关键帧位移、旋转和缩放组合成相对父项的列式仿射矩阵，不使用Time
+// 返回: [16]float64 先缩放、再旋转、后平移的变换, error 姿态数值错误
+func (frame U3DKeyFrame) Matrix() ([16]float64, error) {
+	q, err := frame.quaternion()
+	if err != nil {
+		return [16]float64{}, err
+	}
+	w, x, y, z := q[0], q[1], q[2], q[3]
+	matrix := [16]float64{
+		1 - 2*(y*y+z*z), 2 * (x*y + w*z), 2 * (x*z - w*y), 0,
+		2 * (x*y - w*z), 1 - 2*(x*x+z*z), 2 * (y*z + w*x), 0,
+		2 * (x*z + w*y), 2 * (y*z - w*x), 1 - 2*(x*x+y*y), 0,
+		float64(frame.Displacement[0]), float64(frame.Displacement[1]), float64(frame.Displacement[2]), 1,
+	}
+	for axis, scale := range frame.Scale {
+		for component := range 3 {
+			matrix[axis*4+component] *= float64(scale)
+		}
+	}
+	return matrix, nil
+}
+
+// trackMatrix 按资源和轨道名称采样节点变换，不推测未命名轨道的绑定关系
+// 入参: state 动作轨道状态
+// 返回: [16]float64 节点变换, error 引用、数值或取消错误
+func (r *u3dRender) trackMatrix(state U3DTrackState) ([16]float64, error) {
+	var track *U3DMotionTrack
+	if err := r.ctx.Err(); err != nil {
+		return [16]float64{}, err
+	}
+	if index, exists := r.motionIndex[state.Motion]; exists {
+		motion := &r.model.Motions[index]
+		for i := range motion.Tracks {
+			if i%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return [16]float64{}, err
+				}
+			}
+			if motion.Tracks[i].Name == state.Track {
+				if track != nil {
+					return [16]float64{}, fmt.Errorf("ambiguous U3D motion track %q", state.Track)
+				}
+				track = &motion.Tracks[i]
+			}
+		}
+	}
+	if track == nil {
+		return [16]float64{}, fmt.Errorf("missing U3D motion track %q in %q", state.Track, state.Motion)
+	}
+	frame, err := track.Sample(r.ctx, state.Time, state.Loop)
+	if err != nil {
+		return [16]float64{}, err
+	}
+	return frame.Matrix()
+}

ofdgo_u3d_scene.go

@@ -174,42 +174,42 @@ func u3dTriangleNormal(points [3]u3dVector) u3dVector {
 	return normal.unit()
 }
 
-// instances 按拓扑顺序构建全部父路径实例，限制共享层级的指数展开
+// sceneGraph 校验父子关系并确定拓扑顺序，只有默认根的后代接入场景
-// 入参: limit 最大实例数
+// 返回: []int 拓扑顺序, map[string]int 节点索引, error 结构、预算或取消错误
-// 返回: error 结构、预算、实例上限或取消错误
+func (r *u3dRender) sceneGraph() ([]int, map[string]int, error) {
-func (r *u3dRender) instances(limit int) error {
 	nodes := r.model.Nodes
-	if err := r.reserve(uint64(len(nodes)), 160); err != nil {
+	if err := r.reserve(uint64(len(nodes)), 161); err != nil {
-		return err
+		return nil, nil, err
 	}
 	index := make(map[string]int, len(nodes))
 	for i, node := range nodes {
 		if i%256 == 0 {
 			if err := r.ctx.Err(); err != nil {
-				return err
+				return nil, nil, err
 			}
 		}
 		if _, exists := index[node.Name]; exists || node.Name == "" {
-			return fmt.Errorf("invalid U3D render node name")
+			return nil, nil, fmt.Errorf("invalid U3D render node name")
 		}
 		switch node.Kind {
 		case "Group", "Model", "Light", "View":
 		default:
-			return fmt.Errorf("unsupported U3D render node kind")
+			return nil, nil, fmt.Errorf("unsupported U3D render node kind")
 		}
 		index[node.Name] = i
 	}
 	counts := make([]int, len(nodes))
 	children := make([][]int, len(nodes))
 	r.byNode = make([][]int, len(nodes))
+	r.connected = make([]bool, len(nodes))
 	for i, node := range nodes {
 		if err := r.reserve(uint64(len(node.Parents)), 16); err != nil {
-			return err
+			return nil, nil, err
 		}
 		for k, parent := range node.Parents {
 			if k%256 == 0 {
 				if err := r.ctx.Err(); err != nil {
-					return err
+					return nil, nil, err
 				}
 			}
 			if j, ok := index[parent.Name]; ok {
@@ -222,7 +222,7 @@ func (r *u3dRender) instances(limit int) error {
 	for i, n := range counts {
 		if i%256 == 0 {
 			if err := r.ctx.Err(); err != nil {
-				return err
+				return nil, nil, err
 			}
 		}
 		if n == 0 {
@@ -231,9 +231,54 @@ func (r *u3dRender) instances(limit int) error {
 	}
 	for cursor := 0; cursor < len(queue); cursor++ {
 		if err := r.ctx.Err(); err != nil {
-			return err
+			return nil, nil, err
 		}
 		i := queue[cursor]
+		for j, parent := range nodes[i].Parents {
+			if j%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return nil, nil, err
+				}
+			}
+			if parent.Name == "" {
+				r.connected[i] = true
+				break
+			}
+			if p, exists := index[parent.Name]; exists && r.connected[p] {
+				r.connected[i] = true
+				break
+			}
+		}
+		for childIndex, child := range children[i] {
+			if childIndex%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return nil, nil, err
+				}
+			}
+			counts[child]--
+			if counts[child] == 0 {
+				queue = append(queue, child)
+			}
+		}
+	}
+	if len(queue) != len(nodes) {
+		return nil, nil, fmt.Errorf("cyclic U3D node parents")
+	}
+	return queue, index, nil
+}
+
+// instances 按拓扑顺序展开接入场景的父路径，不将未解析的父节点视为默认根
+// 入参: order 拓扑顺序, index 节点索引, limit 最大实例数
+// 返回: error 变换、预算、实例上限或取消错误
+func (r *u3dRender) instances(order []int, index map[string]int, limit int) error {
+	nodes := r.model.Nodes
+	for _, i := range order {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if !r.connected[i] {
+			continue
+		}
 		state := r.states[nodes[i].Name]
 		for parentIndex, parent := range nodes[i].Parents {
 			if parentIndex%256 == 0 {
@@ -241,20 +286,27 @@ func (r *u3dRender) instances(limit int) error {
 					return err
 				}
 			}
+			parents := []int{-1}
+			if parent.Name != "" {
+				j, exists := index[parent.Name]
+				if !exists || !r.connected[j] {
+					continue
+				}
+				parents = r.byNode[j]
+			}
 			var local u3dMatrix
 			for k, v := range parent.Transform {
 				local[k] = float64(v)
 			}
+			if animation, exists := r.animated[nodes[i].Name]; exists {
+				local = local.multiply(animation.matrix)
+			}
 			if state.Matrix != nil {
 				local = *state.Matrix
 			}
 			if !local.valid() {
 				return fmt.Errorf("unsupported U3D non-affine node transform")
 			}
-			parents := []int{-1}
-			if j, ok := index[parent.Name]; ok {
-				parents = r.byNode[j]
-			}
 			for _, p := range parents {
 				if len(r.scene) >= limit {
 					return fmt.Errorf("U3D instance count exceeds limit")
@@ -284,20 +336,6 @@ func (r *u3dRender) instances(limit int) error {
 				r.scene = append(r.scene, u3dInstance{node: i, parent: p, world: world, opacity: opacity, visibility: visibility})
 			}
 		}
-		for childIndex, child := range children[i] {
-			if childIndex%256 == 0 {
-				if err := r.ctx.Err(); err != nil {
-					return err
 	}
-			}
+	return r.ctx.Err()
-			counts[child]--
-			if counts[child] == 0 {
-				queue = append(queue, child)
-			}
-		}
-	}
-	if len(queue) != len(nodes) {
-		return fmt.Errorf("cyclic U3D node parents")
-	}
-	return nil
 }

ofdgo_u3d_section.go

@@ -44,10 +44,10 @@ func (r *u3dRender) prepareSections(sections []U3DCrossSection) error {
 	if len(sections) == 0 {
 		return nil
 	}
-	if err := r.reserve(uint64(len(sections)), 352); err != nil {
+	if err := r.reserve(uint64(len(sections)), 1152); err != nil {
 		return err
 	}
-	if err := r.reserve(uint64(len(sections))+3, 112); err != nil {
+	if err := r.reserve(uint64(len(sections))+3, 512); err != nil {
 		return err
 	}
 	r.sections = make([]u3dSection, len(sections))
@@ -140,11 +140,10 @@ func (r *u3dRender) sceneDiagonal() (float64, error) {
 			return 0, err
 		}
 		node := r.model.Nodes[instance.node]
-		index, exists := r.meshes[node.Resource]
+		mesh := r.nodeMesh(&node)
-		if node.Kind != "Model" || !exists {
+		if node.Kind != "Model" || mesh == nil {
 			continue
 		}
-		mesh := &r.model.Meshes[index]
 		for i := range len(mesh.Faces) + len(mesh.Lines) + len(mesh.Points) {
 			_, corners := mesh.primitive(i)
 			if i%256 == 0 {

ofdgo_u3d_shader.go

@@ -0,0 +1,303 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"image"
+	"math"
+)
+
+// U3DTextureLayer 保存单个着色器纹理通道，矩阵按列排列
+// Blend依次以0至3表示相乘、相加、替换及线性混合，BlendSource为1时使用BlendConstant
+// Mode依次以0至4表示模型坐标、平面、圆柱、球面及反射映射
+// Alpha控制是否使用纹理透明度，Repeat低两位分别启用横向及纵向平铺
+// 平面映射直接取参考位置的XY；圆柱以Z为纵坐标，圆柱与球面的经线从正X轴朝正Y轴递增
+// 球面纬度从正Z极到负Z极映射为0至1；反射映射使用相机空间球面环境图，图像纵坐标向下
+type U3DTextureLayer struct {
+	Texture                  string
+	Intensity, BlendConstant float32
+	Blend, BlendSource       uint8
+	Mode, Repeat             uint8
+	Alpha                    bool
+	Transform, WrapTransform [16]float32
+}
+
+// u3dTextureSet 保存一次绘制内共用的有序纹理层
+type u3dTextureSet struct {
+	layers                  [8]*U3DTextureLayer
+	images                  [8]*image.NRGBA64
+	wrap                    [8]*[16]float64
+	normal                  u3dMatrix
+	mask                    uint8
+	reflection, perspective bool
+}
+
+// shaderTextures 校验并缓存启用的纹理，未使用的着色器不会触发图像解码
+// 入参: shader 着色器
+// 返回: *u3dTextureSet 纹理组合，空值表示无纹理, error 参数、能力、预算或取消错误
+func (r *u3dRender) shaderTextures(shader U3DShader) (*u3dTextureSet, error) {
+	if shader.Textures == ([8]*U3DTextureLayer{}) {
+		return nil, nil
+	}
+	if err := r.ctx.Err(); err != nil {
+		return nil, err
+	}
+	if cached := r.textureSets[shader.Textures]; cached != nil {
+		return cached, nil
+	}
+	if err := r.reserve(1, 512); err != nil {
+		return nil, err
+	}
+	set := &u3dTextureSet{layers: shader.Textures}
+	for i, layer := range set.layers {
+		if layer == nil {
+			continue
+		}
+		if layer.Blend > 3 || layer.BlendSource > 1 || layer.Mode > 4 || layer.Repeat > 3 || !finite(float64(layer.Intensity)) || !finite(float64(layer.BlendConstant)) {
+			return nil, fmt.Errorf("invalid U3D texture layer")
+		}
+		for _, matrix := range [2][16]float32{layer.Transform, layer.WrapTransform} {
+			for _, value := range matrix {
+				if !finite(float64(value)) {
+					return nil, fmt.Errorf("invalid U3D texture transform")
+				}
+			}
+		}
+		if layer.Mode >= 1 && layer.Mode <= 3 {
+			if err := r.reserve(1, 256); err != nil {
+				return nil, err
+			}
+			inverse, err := u3dTextureInverse(layer.WrapTransform)
+			if err != nil {
+				return nil, err
+			}
+			set.wrap[i] = &inverse
+		}
+		if layer.Mode == 4 && !set.reflection {
+			var ok bool
+			set.normal, ok = r.toCamera.inverse()
+			if !ok {
+				return nil, fmt.Errorf("invalid U3D reflection camera")
+			}
+			set.reflection, set.perspective = true, r.camera.Perspective
+		}
+		img, err := r.texture(layer.Texture)
+		if err != nil {
+			return nil, err
+		}
+		set.images[i] = img
+		set.mask |= 1 << i
+	}
+	if r.textureSets == nil {
+		r.textureSets = make(map[[8]*U3DTextureLayer]*u3dTextureSet)
+	}
+	r.textureSets[shader.Textures] = set
+	return set, nil
+}
+
+// coordinates 保存模型纹理坐标或程序化映射的插值输入，避免经线两侧直接插值
+// 入参: vertex 目标顶点, mesh 几何资源, shading 属性布局, corner 属性索引, normal 世界法线
+// 返回: error 坐标、索引或维度错误
+func (s *u3dTextureSet) coordinates(vertex *u3dVertex, mesh *U3DMesh, shading U3DShading, corner U3DCorner, normal u3dVector) error {
+	if vertex.textureMask != 0 {
+		clear(vertex.texture[:])
+	}
+	vertex.textureMask = 0
+	if s == nil {
+		return nil
+	}
+	vertex.textureMask = s.mask
+	for i, layer := range s.layers {
+		if layer == nil {
+			continue
+		}
+		if layer.Mode != 0 {
+			if layer.Mode == 4 {
+				vertex.texture[i] = s.normal.normal(normal)
+				if vertex.texture[i] == ([3]float64{}) {
+					return fmt.Errorf("invalid U3D reflection normal")
+				}
+			} else {
+				if uint64(corner.Position) >= uint64(len(mesh.Positions)) {
+					return fmt.Errorf("invalid U3D texture position index")
+				}
+				for c, value := range mesh.Positions[corner.Position] {
+					if !finite(float64(value)) {
+						return fmt.Errorf("invalid U3D texture position")
+					}
+					vertex.texture[i][c] = float64(value)
+				}
+			}
+			continue
+		}
+		if i >= len(shading.TextureDimensions) || uint64(corner.Texture[i]) >= uint64(len(mesh.TextureCoordinates)) {
+			return fmt.Errorf("invalid U3D texture coordinate index")
+		}
+		dimension := shading.TextureDimensions[i]
+		if dimension < 1 || dimension > 4 {
+			return fmt.Errorf("invalid U3D texture coordinate dimensions")
+		}
+		value := [4]float64{0, 0, 0, 1}
+		for component := range dimension {
+			v := float64(mesh.TextureCoordinates[corner.Texture[i]][component])
+			if !finite(v) {
+				return fmt.Errorf("invalid U3D texture coordinate")
+			}
+			value[component] = v
+		}
+		for component, row := range [3]int{0, 1, 3} {
+			total := 0.0
+			for col, v := range value {
+				total += float64(layer.Transform[col*4+row]) * v
+			}
+			if !finite(total) {
+				return fmt.Errorf("invalid U3D transformed texture coordinate")
+			}
+			vertex.texture[i][component] = total
+		}
+	}
+	return nil
+}
+
+// textureColor 合成纹理后恢复节点指定的透明度，再叠加视图透明度
+// 入参: textures 纹理组合, color 顶点插值颜色, coordinates 纹理输入, position 相机空间位置, override 是否指定节点透明度
+// 返回: error 纹理映射或混合错误
+func (r *u3dRender) textureColor(textures *u3dTextureSet, color *[4]float64, coordinates *[8][3]float64, position u3dVector, override bool) error {
+	if textures == nil {
+		return nil
+	}
+	opacity := color[3]
+	if err := textures.color(color, coordinates, position); err != nil {
+		return err
+	}
+	if override {
+		color[3] = opacity
+	}
+	if r.opacity >= 0 {
+		color[3] *= r.opacity
+	}
+	return nil
+}
+
+// color 按通道顺序合成纹理，在透明度覆盖、透明测试和雾效之前执行
+// 入参: color 未预乘底色, coordinates 插值后的纹理输入, position 相机空间位置
+// 返回: error 无效投影坐标或混合结果
+func (s *u3dTextureSet) color(color *[4]float64, coordinates *[8][3]float64, position u3dVector) error {
+	if s == nil {
+		return nil
+	}
+	for i, layer := range s.layers {
+		if layer == nil {
+			continue
+		}
+		uv := coordinates[i]
+		if layer.Mode != 0 {
+			var err error
+			uv, err = s.generated(i, uv, position)
+			if err != nil {
+				return err
+			}
+		}
+		u, v := uv[0]/uv[2], uv[1]/uv[2]
+		if !finite(u) || !finite(v) {
+			return fmt.Errorf("invalid U3D projected texture coordinate")
+		}
+		sample := u3dShaderSample(s.images[i], u, v, layer.Repeat, layer.Alpha)
+		for c := range 3 {
+			sample[c] *= float64(layer.Intensity)
+		}
+		weight := sample[3]
+		if layer.BlendSource == 1 {
+			weight = min(1, max(0, float64(layer.BlendConstant)))
+		}
+		for c := range color {
+			switch layer.Blend {
+			case 0:
+				color[c] *= sample[c]
+			case 1:
+				color[c] += sample[c]
+			case 2:
+				color[c] = sample[c]
+			case 3:
+				color[c] = sample[c]*weight + color[c]*(1-weight)
+			}
+			if !finite(color[c]) {
+				return fmt.Errorf("invalid U3D texture blend result")
+			}
+			color[c] = min(1, max(0, color[c]))
+		}
+	}
+	return nil
+}
+
+// u3dShaderSample 按归一化坐标采样纹理，平铺时跨边界插值，未平铺时钳制边缘
+// 全透明采样保留原始RGB，供相加、固定权重混合及透明度覆盖使用
+// 入参: texture 纹理, u 横坐标, v 纵坐标, repeat 平铺位图, alpha 是否使用透明度
+// 返回: [4]float64 未预乘颜色及透明度
+func u3dShaderSample(texture *image.NRGBA64, u, v float64, repeat uint8, alpha bool) [4]float64 {
+	if repeat&1 != 0 {
+		u -= math.Floor(u)
+	} else {
+		u = min(1, max(0, u))
+	}
+	if repeat&2 != 0 {
+		v -= math.Floor(v)
+	} else {
+		v = min(1, max(0, v))
+	}
+	w, h := texture.Rect.Dx(), texture.Rect.Dy()
+	x, y := u*float64(w)-.5, v*float64(h)-.5
+	x0, y0 := int(math.Floor(x)), int(math.Floor(y))
+	fx, fy := x-float64(x0), y-float64(y0)
+	wx, wy := [2]float64{1 - fx, fx}, [2]float64{1 - fy, fy}
+	var result [4]float64
+	var transparent [3]float64
+	for row := range 2 {
+		py := min(h-1, max(0, y0+row))
+		if repeat&2 != 0 {
+			py = (y0 + row + h) % h
+		}
+		for col := range 2 {
+			px := min(w-1, max(0, x0+col))
+			if repeat&1 != 0 {
+				px = (x0 + col + w) % w
+			}
+			c := texture.NRGBA64At(px, py)
+			a := 1.0
+			if alpha {
+				a = float64(c.A) / 65535
+			}
+			weight := wx[col] * wy[row]
+			if a == 0 {
+				transparent[0] += float64(c.R) / 65535 * weight
+				transparent[1] += float64(c.G) / 65535 * weight
+				transparent[2] += float64(c.B) / 65535 * weight
+			}
+			result[0] += float64(c.R) / 65535 * a * weight
+			result[1] += float64(c.G) / 65535 * a * weight
+			result[2] += float64(c.B) / 65535 * a * weight
+			result[3] += a * weight
+		}
+	}
+	if result[3] != 0 {
+		for c := range 3 {
+			result[c] /= result[3]
+		}
+	} else {
+		copy(result[:3], transparent[:])
+	}
+	return result
+}

ofdgo_u3d_skeleton.go

@@ -0,0 +1,103 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"io"
+)
+
+// U3DBone 保存相对父骨骼的初始位姿，Orientation按W、X、Y、Z排列
+// Attributes标志决定链接、关节字段是否存在，以及各轴旋转约束是否启用和限幅
+// RotationConstraints按X、Y、Z轴排列，每项依次为上限、下限；未指定骨骼姿态时不变形
+type U3DBone struct {
+	Name, Parent         string
+	Attributes           uint32
+	Length               float32
+	Displacement         [3]float32
+	Orientation          [4]float32
+	LinkCount            uint32
+	LinkLength           float32
+	StartJoint, EndJoint U3DBoneJoint
+	RotationConstraints  [3][2]float32
+}
+
+// U3DBoneJoint 保存骨骼局部坐标系内关节椭圆的中心偏移和两轴尺寸
+type U3DBoneJoint struct {
+	Center, Scale [2]float32
+}
+
+// skeleton 按ECMA-363第9.6.1.1.6节读取骨架，三角网格、点集和线集共用
+// 入参: r 字段读取器
+// 返回: []U3DBone 按父项在前排列的骨骼, error 结构、预算或取消错误
+func (d *u3dDecoder) skeleton(r *u3dValues) ([]U3DBone, error) {
+	count := r.u32()
+	if r.err != nil {
+		return nil, r.err
+	}
+	if count == 0 {
+		return nil, nil
+	}
+	if uint64(count) > uint64(len(r.data)-r.pos)/64 {
+		return nil, io.ErrUnexpectedEOF
+	}
+	if err := d.reserve(uint64(count), 256); err != nil {
+		return nil, err
+	}
+	bones := make([]U3DBone, int(count))
+	names := make(map[string]bool, int(count))
+	for index := range bones {
+		if index%256 == 0 {
+			if err := d.ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
+		bone := &bones[index]
+		bone.Name, bone.Parent = r.text(), r.text()
+		bone.Attributes, bone.Length = r.u32(), r.f32()
+		for component := range bone.Displacement {
+			bone.Displacement[component] = r.f32()
+		}
+		for component := range bone.Orientation {
+			bone.Orientation[component] = r.f32()
+		}
+		if bone.Attributes&1 != 0 {
+			bone.LinkCount, bone.LinkLength = r.u32(), r.f32()
+		}
+		if bone.Attributes&2 != 0 {
+			for _, joint := range []*U3DBoneJoint{&bone.StartJoint, &bone.EndJoint} {
+				joint.Center = [2]float32{r.f32(), r.f32()}
+				joint.Scale = [2]float32{r.f32(), r.f32()}
+			}
+		}
+		for axis := range bone.RotationConstraints {
+			bone.RotationConstraints[axis] = [2]float32{r.f32(), r.f32()}
+		}
+		if r.err != nil {
+			return nil, r.err
+		}
+		if bone.Attributes & ^uint32(255) != 0 {
+			return nil, fmt.Errorf("invalid U3D bone attributes")
+		}
+		if names[bone.Name] {
+			return nil, fmt.Errorf("duplicate U3D bone %q", bone.Name)
+		}
+		if index == 0 && bone.Parent != "" || index != 0 && !names[bone.Parent] {
+			return nil, fmt.Errorf("invalid U3D bone parent %q", bone.Parent)
+		}
+		names[bone.Name] = true
+	}
+	return bones, nil
+}

ofdgo_u3d_skin.go

@@ -0,0 +1,505 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"math"
+	"slices"
+)
+
+// U3DBoneState 按骨骼名称指定相对父骨骼末端的姿态，根骨骼相对模型原点
+// Frame可由动作轨道采样得到，Time不参与变形；单位缩放需显式设为[3]float32{1, 1, 1}
+// 未覆盖项沿用文件或动画求值后的局部姿态，重复名称使用最后一项，不施加逆运动学约束
+type U3DBoneState struct {
+	Name  string
+	Frame U3DKeyFrame
+}
+
+// u3dSkinBone 保存初始姿态到当前姿态的变换及其逆矩阵
+type u3dSkinBone struct {
+	matrix, inverse u3dMatrix
+	invertible      bool
+}
+
+// u3dSkinPose 保存同一几何最近求值的姿态和权重，仅用于本次绘制
+type u3dSkinPose struct {
+	weights *U3DBoneWeights
+	states  []U3DBoneState
+	mesh    *U3DMesh
+}
+
+// nodeMesh 返回节点本次绘制使用的几何，未变形节点直接引用原资源
+// 入参: node 模型节点
+// 返回: *U3DMesh 几何，资源缺失时为空
+func (r *u3dRender) nodeMesh(node *U3DNode) *U3DMesh {
+	if mesh := r.posed[node.Name]; mesh != nil {
+		return mesh
+	}
+	if index, exists := r.meshes[node.Resource]; exists {
+		return &r.model.Meshes[index]
+	}
+	return nil
+}
+
+// poseNodes 应用动画和显式骨骼姿态，同源同姿态的节点及父路径共用变形几何
+// 返回: error 骨架、权重、预算或取消错误
+func (r *u3dRender) poseNodes() error {
+	if len(r.states) == 0 && len(r.animated) == 0 {
+		return r.ctx.Err()
+	}
+	var cache map[*U3DMesh]u3dSkinPose
+	var cacheBytes uint64
+	defer func() { r.remaining += cacheBytes }()
+	for i := range r.model.Nodes {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		if r.connected != nil && !r.connected[i] {
+			continue
+		}
+		node := &r.model.Nodes[i]
+		states := r.states[node.Name].Bones
+		animation := r.animated[node.Name]
+		if len(states) == 0 && len(animation.bones) == 0 {
+			continue
+		}
+		mesh := r.nodeMesh(node)
+		if node.Kind != "Model" || mesh == nil {
+			return fmt.Errorf("missing U3D bone state geometry for %q", node.Name)
+		}
+		if r.posed == nil {
+			if err := r.reserve(1, 1024); err != nil {
+				return err
+			}
+			r.posed = make(map[string]*U3DMesh)
+		}
+		if err := r.reserve(1, 128); err != nil {
+			return err
+		}
+		var temporary uint64
+		if len(animation.bones) != 0 {
+			if len(states) == 0 {
+				states = animation.bones
+			} else {
+				count := uint64(len(animation.bones)) + uint64(len(states))
+				if err := r.reserve(count, 64); err != nil {
+					return err
+				}
+				temporary = count * 64
+				combined := make([]U3DBoneState, len(animation.bones), int(count))
+				copy(combined, animation.bones)
+				states = append(combined, states...)
+			}
+		}
+		weights := animation.weights
+		if weights == nil {
+			var err error
+			weights, err = r.skinWeightSource(mesh, node.BoneWeights, math.MaxUint64, math.MaxUint64)
+			if err != nil {
+				r.remaining += temporary
+				return err
+			}
+		}
+		previous, exists := cache[mesh]
+		shared := exists && previous.weights == weights && len(previous.states) == len(states)
+		if shared {
+			for j := range states {
+				if j%256 == 0 {
+					if err := r.ctx.Err(); err != nil {
+						r.remaining += temporary
+						return err
+					}
+				}
+				if states[j] != previous.states[j] {
+					shared = false
+					break
+				}
+			}
+		}
+		if shared {
+			r.posed[node.Name] = previous.mesh
+			r.remaining += temporary
+			continue
+		}
+		source, sets := mesh, node.BoneWeights
+		if animation.weights != nil {
+			geometry := *mesh
+			geometry.BoneWeights = []U3DBoneWeights{*animation.weights}
+			mesh, sets = &geometry, nil
+		}
+		posed, err := r.skinMesh(mesh, sets, states)
+		if err != nil {
+			r.remaining += temporary
+			return err
+		}
+		r.posed[node.Name] = posed
+		if len(r.model.Nodes) > 1 {
+			if cache == nil {
+				if err := r.reserve(1, 1024); err != nil {
+					return err
+				}
+				cacheBytes += 1024
+				cache = make(map[*U3DMesh]u3dSkinPose)
+			}
+			if !exists {
+				if err := r.reserve(1, 128); err != nil {
+					return err
+				}
+				cacheBytes += 128
+			}
+			if err := r.reserve(uint64(len(states)), 64); err != nil {
+				return err
+			}
+			cacheBytes += uint64(len(states)) * 64
+			saved := make([]U3DBoneState, len(states))
+			copy(saved, states)
+			cache[source] = u3dSkinPose{weights: weights, states: saved, mesh: posed}
+			released := uint64(len(previous.states)) * 64
+			r.remaining += released
+			cacheBytes -= released
+		}
+		r.remaining += temporary
+	}
+	return r.ctx.Err()
+}
+
+// boneTransforms 连接骨骼局部姿态，以初始姿态的逆变换将作者坐标映射到当前姿态
+// 入参: bones 按父项在前排列的骨架, states 显式姿态
+// 返回: []u3dSkinBone 变形矩阵, error 骨架、姿态或取消错误
+func (r *u3dRender) boneTransforms(bones []U3DBone, states []U3DBoneState) ([]u3dSkinBone, error) {
+	index := make(map[string]int, len(bones))
+	for i, bone := range bones {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
+		if _, exists := index[bone.Name]; exists {
+			return nil, fmt.Errorf("duplicate U3D bone %q", bone.Name)
+		}
+		index[bone.Name] = i
+	}
+	overrides := make(map[int]U3DKeyFrame, min(len(states), len(bones)))
+	for i, state := range states {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
+		bone, exists := index[state.Name]
+		if !exists {
+			return nil, fmt.Errorf("missing U3D bone %q", state.Name)
+		}
+		overrides[bone] = state.Frame
+	}
+	bind, pose := make([]u3dMatrix, len(bones)), make([]u3dMatrix, len(bones))
+	result := make([]u3dSkinBone, len(bones))
+	for i, bone := range bones {
+		if err := r.ctx.Err(); err != nil {
+			return nil, err
+		}
+		if !finite(float64(bone.Length)) || bone.Length < 0 || bone.Attributes & ^uint32(255) != 0 {
+			return nil, fmt.Errorf("invalid U3D bone parameters")
+		}
+		if bone.Attributes&1 != 0 && bone.LinkCount != 0 {
+			return nil, fmt.Errorf("unsupported U3D bone link deformation")
+		}
+		initial := U3DKeyFrame{Displacement: bone.Displacement, Rotation: bone.Orientation, Scale: [3]float32{1, 1, 1}}
+		base, err := initial.Matrix()
+		if err != nil {
+			return nil, err
+		}
+		current := base
+		if frame, exists := overrides[i]; exists {
+			current, err = frame.Matrix()
+			if err != nil {
+				return nil, err
+			}
+		}
+		bind[i], pose[i] = u3dMatrix(base), u3dMatrix(current)
+		if i == 0 {
+			if bone.Parent != "" {
+				return nil, fmt.Errorf("invalid U3D root bone parent")
+			}
+		} else {
+			parent, exists := index[bone.Parent]
+			if !exists || parent >= i {
+				return nil, fmt.Errorf("invalid U3D bone parent %q", bone.Parent)
+			}
+			end := u3dIdentity()
+			end[12] = float64(bones[parent].Length)
+			bind[i] = bind[parent].multiply(end).multiply(bind[i])
+			pose[i] = pose[parent].multiply(end).multiply(pose[i])
+		}
+		inverse, ok := bind[i].inverse()
+		if !ok || !pose[i].valid() {
+			return nil, fmt.Errorf("invalid U3D bone transform")
+		}
+		result[i].matrix = pose[i].multiply(inverse)
+		if !result[i].matrix.valid() {
+			return nil, fmt.Errorf("invalid U3D bone deformation")
+		}
+		result[i].inverse, result[i].invertible = result[i].matrix.inverse()
+	}
+	return result, nil
+}
+
+// skinWeights 选取与几何类型相符的末项权重，节点链覆盖资源链
+// 入参: mesh 原始几何, sets 节点权重
+// 返回: *U3DBoneWeights 有效权重, error 类型、引用或取消错误
+func (r *u3dRender) skinWeights(mesh *U3DMesh, sets []U3DBoneWeights) (*U3DBoneWeights, error) {
+	return r.skinWeightSet(mesh, sets, math.MaxUint64, math.MaxUint64)
+}
+
+// skinWeightSource 按修饰链截止位置选取权重，不使用动画后面的权重输出
+// 入参: mesh 原始几何, sets 节点权重, resourceEnd、nodeEnd 两条链中首个不参与的索引
+// 返回: *U3DBoneWeights 权重来源，内容尚未校验, error 类型、引用或取消错误
+func (r *u3dRender) skinWeightSource(mesh *U3DMesh, sets []U3DBoneWeights, resourceEnd, nodeEnd uint64) (*U3DBoneWeights, error) {
+	kind := uint32(0)
+	for i, count := range []int{len(mesh.Faces), len(mesh.Lines), len(mesh.Points)} {
+		if count != 0 {
+			if kind != 0 {
+				return nil, fmt.Errorf("unsupported U3D mixed geometry deformation")
+			}
+			kind = 1 << i
+		}
+	}
+	var selected *U3DBoneWeights
+	for chain, group := range [][]U3DBoneWeights{mesh.BoneWeights, sets} {
+		end := resourceEnd
+		if chain != 0 {
+			end = nodeEnd
+		}
+		var last *U3DBoneWeights
+		for i := range group {
+			if i%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return nil, err
+				}
+			}
+			if uint64(group[i].Index) < end && group[i].Attributes == kind && (last == nil || group[i].Index > last.Index) {
+				last = &group[i]
+			}
+		}
+		if last != nil {
+			selected = last
+		}
+	}
+	if selected == nil {
+		return nil, fmt.Errorf("unsupported U3D deformation without bone weights")
+	}
+	return selected, r.ctx.Err()
+}
+
+// skinWeightSet 选取并校验指定修饰链位置之前的权重
+// 入参: mesh 原始几何, sets 节点权重, resourceEnd、nodeEnd 两条链中首个不参与的索引
+// 返回: *U3DBoneWeights 有效权重, error 类型、引用、数值或取消错误
+func (r *u3dRender) skinWeightSet(mesh *U3DMesh, sets []U3DBoneWeights, resourceEnd, nodeEnd uint64) (*U3DBoneWeights, error) {
+	selected, err := r.skinWeightSource(mesh, sets, resourceEnd, nodeEnd)
+	if err != nil {
+		return nil, err
+	}
+	if selected.Index == 0 || len(selected.Offsets) == 0 || len(selected.Offsets)-1 > len(mesh.Positions) || selected.Offsets[0] != 0 || uint64(selected.Offsets[len(selected.Offsets)-1]) != uint64(len(selected.Weights)) {
+		return nil, fmt.Errorf("invalid U3D bone weight offsets")
+	}
+	for i := 1; i < len(selected.Offsets); i++ {
+		if err := r.ctx.Err(); err != nil {
+			return nil, err
+		}
+		start, end := selected.Offsets[i-1], selected.Offsets[i]
+		if end < start || uint64(end) > uint64(len(selected.Weights)) {
+			return nil, fmt.Errorf("invalid U3D bone weight range")
+		}
+		var total float64
+		for j, weight := range selected.Weights[start:end] {
+			if j%256 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return nil, err
+				}
+			}
+			if uint64(weight.Bone) >= uint64(len(mesh.Bones)) || !finite(float64(weight.Weight)) || weight.Weight < 0 {
+				return nil, fmt.Errorf("invalid U3D bone weight")
+			}
+			total += float64(weight.Weight)
+		}
+		if start != end && math.Abs(total-1) > 1e-6 {
+			return nil, fmt.Errorf("invalid U3D bone weight sum")
+		}
+	}
+	return selected, nil
+}
+
+// influence 返回指定位置的骨骼权重，未提供权重的位置保持不变
+// 入参: position 作者位置索引
+// 返回: []U3DBoneWeight 影响列表
+func (weights *U3DBoneWeights) influence(position uint32) []U3DBoneWeight {
+	if uint64(position)+1 >= uint64(len(weights.Offsets)) {
+		return nil
+	}
+	return weights.Weights[weights.Offsets[position]:weights.Offsets[position+1]]
+}
+
+// skinVector 对位置或法线应用加权骨骼变换，法线在累加后统一归一化
+// 入参: value 原向量, weights 位置权重, bones 骨骼变换, normal 是否处理法线
+// 返回: [3]float32 变形结果, error 数值、奇异变换或取消错误
+func (r *u3dRender) skinVector(value [3]float32, weights []U3DBoneWeight, bones []u3dSkinBone, normal bool) ([3]float32, error) {
+	input := u3dVector{float64(value[0]), float64(value[1]), float64(value[2])}
+	for _, component := range input {
+		if !finite(component) {
+			return [3]float32{}, fmt.Errorf("invalid U3D skin vector")
+		}
+	}
+	if len(weights) == 0 {
+		return value, nil
+	}
+	var result u3dVector
+	for i, weight := range weights {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return [3]float32{}, err
+			}
+		}
+		if weight.Weight == 0 {
+			continue
+		}
+		bone := &bones[weight.Bone]
+		v := bone.matrix.point(input)
+		if normal {
+			if !bone.invertible {
+				return [3]float32{}, fmt.Errorf("unsupported U3D singular bone normal transform")
+			}
+			m := bone.inverse
+			v = u3dVector{m[0]*input[0] + m[1]*input[1] + m[2]*input[2], m[4]*input[0] + m[5]*input[1] + m[6]*input[2], m[8]*input[0] + m[9]*input[1] + m[10]*input[2]}
+		}
+		for axis := range result {
+			result[axis] += v[axis] * float64(weight.Weight)
+		}
+	}
+	for _, component := range result {
+		if !finite(component) {
+			return [3]float32{}, fmt.Errorf("invalid U3D skin result")
+		}
+	}
+	if normal {
+		result = result.unit()
+	}
+	for axis := range value {
+		value[axis] = float32(result[axis])
+		if !finite(float64(value[axis])) {
+			return [3]float32{}, fmt.Errorf("U3D skin result exceeds range")
+		}
+	}
+	return value, nil
+}
+
+// skinMesh 复制受变形影响的属性，按位置与法线的组合保留独立法线索引
+// 入参: mesh 原始几何, sets 节点权重, states 显式骨骼姿态
+// 返回: *U3DMesh 独立姿态几何, error 结构、能力、预算或取消错误
+func (r *u3dRender) skinMesh(mesh *U3DMesh, sets []U3DBoneWeights, states []U3DBoneState) (*U3DMesh, error) {
+	weights, err := r.skinWeights(mesh, sets)
+	if err != nil {
+		return nil, err
+	}
+	if err := r.reserve(uint64(len(mesh.Bones)), 768); err != nil {
+		return nil, err
+	}
+	if err := r.reserve(uint64(len(states)), 128); err != nil {
+		r.remaining += uint64(len(mesh.Bones)) * 768
+		return nil, err
+	}
+	temporary := uint64(len(mesh.Bones))*768 + uint64(len(states))*128
+	defer func() { r.remaining += temporary }()
+	bones, err := r.boneTransforms(mesh.Bones, states)
+	if err != nil {
+		return nil, err
+	}
+	if err := r.reserve(1, 768); err != nil {
+		return nil, err
+	}
+	if err := r.reserve(uint64(len(mesh.Positions)), 12); err != nil {
+		return nil, err
+	}
+	result := *mesh
+	result.Positions = make([][3]float32, len(mesh.Positions))
+	for i, position := range mesh.Positions {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
+		result.Positions[i], err = r.skinVector(position, weights.influence(uint32(i)), bones, false)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if mesh.ExcludeNormals {
+		return &result, r.ctx.Err()
+	}
+	bytes := uint64(len(mesh.Faces))*148 + uint64(len(mesh.Lines))*100 + uint64(len(mesh.Points))*52
+	if err := r.reserve(bytes, 1); err != nil {
+		return nil, err
+	}
+	result.Faces, result.Lines, result.Points = slices.Clone(mesh.Faces), slices.Clone(mesh.Lines), slices.Clone(mesh.Points)
+	result.Normals = nil
+	if err := r.reserve(1, 1024); err != nil {
+		return nil, err
+	}
+	index := make(map[[2]uint32]uint32)
+	defer func() { r.remaining += 1024 + uint64(len(index))*96 }()
+	for i := range len(result.Faces) + len(result.Lines) + len(result.Points) {
+		if i%256 == 0 {
+			if err := r.ctx.Err(); err != nil {
+				return nil, err
+			}
+		}
+		_, corners := result.primitive(i)
+		for j := range corners {
+			corner := &corners[j]
+			if uint64(corner.Position) >= uint64(len(mesh.Positions)) || uint64(corner.Normal) >= uint64(len(mesh.Normals)) {
+				return nil, fmt.Errorf("invalid U3D skin corner index")
+			}
+			key := [2]uint32{corner.Position, corner.Normal}
+			normal, exists := index[key]
+			if !exists {
+				if err := r.reserve(1, 96); err != nil {
+					return nil, err
+				}
+				if len(result.Normals) == cap(result.Normals) {
+					capacity := max(16, uint64(cap(result.Normals))*2)
+					if capacity > math.MaxUint32 {
+						return nil, fmt.Errorf("U3D skin normal count exceeds limit")
+					}
+					if err := r.reserve(capacity, 12); err != nil {
+						return nil, err
+					}
+					grown := make([][3]float32, len(result.Normals), int(capacity))
+					copy(grown, result.Normals)
+					r.remaining += uint64(cap(result.Normals)) * 12
+					result.Normals = grown
+				}
+				value, err := r.skinVector(mesh.Normals[corner.Normal], weights.influence(corner.Position), bones, true)
+				if err != nil {
+					return nil, err
+				}
+				normal = uint32(len(result.Normals))
+				index[key] = normal
+				result.Normals = append(result.Normals, value)
+			}
+			corner.Normal = normal
+		}
+	}
+	return &result, r.ctx.Err()
+}

ofdgo_u3d_state.go

@@ -18,25 +18,38 @@ import "fmt"
 
 // U3DNodeState 按名称覆盖节点，未指定透明度或可见性时沿父路径继承
 // Opacity范围为0到1，采用标准透明混合；Matrix为相对父节点的列式仿射矩阵
-// 未匹配的名称不影响场景，矩阵为空时保留每条父路径的原始变换
+// 显式Opacity覆盖材质和纹理合成的透明度，之后仍应用视图附加透明度
+// 未匹配的名称不影响场景，Matrix和Motion均为空时保留每条父路径的原始变换
+// Motion以指定轨道替换节点变换，与Matrix互斥，不驱动骨架；显式变换优先于动画修饰器
+// Bones覆盖动画求值后的指定骨骼姿态，未指定项沿用当前局部变换，不修改共享几何
 type U3DNodeState struct {
 	Name    string
 	Opacity *float64
 	Visible *bool
 	Matrix  *[16]float64
+	Motion  *U3DTrackState
+	Bones   []U3DBoneState
 }
 
 // nodeStates 建立有预算限制的覆盖索引，重复名称整体替换而不合并字段
-// 入参: states 节点覆盖
+// 入参: groups 按优先级递增排列的节点覆盖分组
 // 返回: error 数值、预算或取消错误
-func (r *u3dRender) nodeStates(states []U3DNodeState) error {
+func (r *u3dRender) nodeStates(groups ...[]U3DNodeState) error {
-	if len(states) == 0 {
+	var count uint64
+	for _, states := range groups {
+		if uint64(len(states)) > ^uint64(0)-count {
+			return fmt.Errorf("U3D node state count exceeds limit")
+		}
+		count += uint64(len(states))
+	}
+	if count == 0 {
 		return nil
 	}
-	if err := r.reserve(uint64(len(states)), 128); err != nil {
+	if err := r.reserve(count, 160); err != nil {
 		return err
 	}
-	r.states = make(map[string]U3DNodeState, len(states))
+	r.states = make(map[string]U3DNodeState, int(count))
+	for _, states := range groups {
 		for i, state := range states {
 			if i%256 == 0 {
 				if err := r.ctx.Err(); err != nil {
@@ -45,7 +58,14 @@ func (r *u3dRender) nodeStates(states []U3DNodeState) error {
 			}
 			r.states[state.Name] = state
 		}
-	for _, state := range r.states {
+	}
+	var samples map[U3DTrackState]*[16]float64
+	defer func() {
+		if samples != nil {
+			r.remaining += 1024 + uint64(len(samples))*192
+		}
+	}()
+	for name, state := range r.states {
 		if err := r.ctx.Err(); err != nil {
 			return err
 		}
@@ -55,6 +75,31 @@ func (r *u3dRender) nodeStates(states []U3DNodeState) error {
 		if state.Matrix != nil && !u3dMatrix(*state.Matrix).valid() {
 			return fmt.Errorf("invalid U3D node matrix")
 		}
+		if state.Motion != nil {
+			if state.Matrix != nil || !finite(state.Motion.Time) {
+				return fmt.Errorf("invalid U3D node motion state")
+			}
+			if samples == nil {
+				if err := r.reserve(1, 1024); err != nil {
+					return err
+				}
+				samples = make(map[U3DTrackState]*[16]float64)
+			}
+			matrix := samples[*state.Motion]
+			if matrix == nil {
+				if err := r.reserve(1, 320); err != nil {
+					return err
+				}
+				value, err := r.trackMatrix(*state.Motion)
+				if err != nil {
+					return err
+				}
+				matrix = &value
+				samples[*state.Motion] = matrix
+			}
+			state.Matrix = matrix
+			r.states[name] = state
+		}
 	}
 	return nil
 }

ofdgo_u3d_texture.go

@@ -0,0 +1,179 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import "fmt"
+
+// U3DTexture 保存纹理尺寸、图像类型及各通道的图像数据
+type U3DTexture struct {
+	Name          string
+	Width, Height uint32
+	ImageType     uint8
+	Images        []U3DTextureImage
+}
+
+// U3DTextureImage 保存压缩格式、通道位图及完整压缩数据，外部图像仅保留候选URL
+// Compression依次以1至4表示JPEG-24、PNG、JPEG-8和TIFF，ByteCount仅用于内置图像
+type U3DTextureImage struct {
+	Compression uint8
+	Channels    uint8
+	External    bool
+	ByteCount   uint32
+	Data        []byte
+	URLs        []string
+}
+
+// u3dTextureChannels 将亮度通道展开为RGB覆盖位，保留透明度位
+// 入参: channels 标准通道位图
+// 返回: uint8 实际覆盖通道
+func u3dTextureChannels(channels uint8) uint8 {
+	if channels&16 != 0 {
+		channels = channels&^16 | 14
+	}
+	return channels
+}
+
+// textureDeclaration 按ECMA-363第9.8.5.1节读取纹理及通道图像声明
+// 入参: r 字段读取器, name 纹理名称
+// 返回: error 格式、预算或取消错误
+func (d *u3dDecoder) textureDeclaration(r *u3dValues, name string) error {
+	if _, exists := d.textures[name]; exists {
+		return fmt.Errorf("duplicate U3D texture %q", name)
+	}
+	texture := U3DTexture{Name: name, Height: r.u32(), Width: r.u32(), ImageType: r.u8()}
+	if texture.Width == 0 || texture.Height == 0 {
+		return fmt.Errorf("invalid U3D texture dimensions")
+	}
+	switch texture.ImageType {
+	case 1, 14, 15, 16, 17:
+	default:
+		return fmt.Errorf("invalid U3D texture image type")
+	}
+	count := r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	if count == 0 || count > 4 || uint64(count) > uint64(len(r.data)-r.pos)/8 {
+		return fmt.Errorf("invalid U3D continuation image count")
+	}
+	if err := d.reserve(uint64(count), 64); err != nil {
+		return err
+	}
+	texture.Images = make([]U3DTextureImage, int(count))
+	var covered uint8
+	for n := range texture.Images {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		image := &texture.Images[n]
+		image.Compression, image.Channels = r.u8(), r.u8()
+		attributes := uint16(r.u8()) | uint16(r.u8())<<8
+		if r.err != nil {
+			return r.err
+		}
+		channels := u3dTextureChannels(image.Channels)
+		if image.Compression < 1 || image.Compression > 4 || image.Channels == 0 || image.Channels&^uint8(31) != 0 || attributes > 1 || covered&channels != 0 || channels&^u3dTextureChannels(texture.ImageType) != 0 {
+			return fmt.Errorf("invalid U3D continuation image format")
+		}
+		covered |= channels
+		image.External = attributes == 1
+		if !image.External {
+			image.ByteCount = r.u32()
+			continue
+		}
+		count := r.u32()
+		if r.err != nil {
+			return r.err
+		}
+		if uint64(count) > uint64(len(r.data)-r.pos)/2 {
+			return fmt.Errorf("invalid U3D texture URL count")
+		}
+		if err := d.reserve(uint64(count), 16); err != nil {
+			return err
+		}
+		image.URLs = make([]string, int(count))
+		for i := range image.URLs {
+			if err := d.ctx.Err(); err != nil {
+				return err
+			}
+			image.URLs[i] = r.text()
+			if r.err != nil {
+				return r.err
+			}
+		}
+	}
+	if err := r.done(); err != nil {
+		return err
+	}
+	if covered != u3dTextureChannels(texture.ImageType) {
+		return fmt.Errorf("incomplete U3D texture channels")
+	}
+	if d.textures == nil {
+		d.textures = make(map[string]int)
+	}
+	d.textures[name] = len(d.model.Textures)
+	d.model.Textures = append(d.model.Textures, texture)
+	return nil
+}
+
+// textureContinuation 按声明长度合并纹理分片，不与输入共享存储
+// 入参: r 字段读取器, name 纹理名称
+// 返回: error 格式、预算或取消错误
+func (d *u3dDecoder) textureContinuation(r *u3dValues, name string) error {
+	index := r.u32()
+	if r.err != nil {
+		return r.err
+	}
+	texture, exists := d.textures[name]
+	if !exists || uint64(index) >= uint64(len(d.model.Textures[texture].Images)) {
+		return fmt.Errorf("invalid U3D texture continuation reference")
+	}
+	image := &d.model.Textures[texture].Images[index]
+	data := r.take(len(r.data) - r.pos)
+	if image.External || uint64(len(image.Data))+uint64(len(data)) > uint64(image.ByteCount) {
+		return fmt.Errorf("invalid U3D texture continuation length")
+	}
+	if image.Data == nil {
+		if err := d.reserve(uint64(image.ByteCount), 1); err != nil {
+			return err
+		}
+		image.Data = make([]byte, 0, int(image.ByteCount))
+	}
+	for len(data) != 0 {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		count := min(65536, len(data))
+		image.Data = append(image.Data, data[:count]...)
+		data = data[count:]
+	}
+	return d.ctx.Err()
+}
+
+// checkTextures 确认各通道的内置图像完整，不加载外部引用
+// 返回: error 缺失分片或取消错误
+func (d *u3dDecoder) checkTextures() error {
+	for _, texture := range d.model.Textures {
+		for _, image := range texture.Images {
+			if err := d.ctx.Err(); err != nil {
+				return err
+			}
+			if !image.External && uint64(len(image.Data)) != uint64(image.ByteCount) {
+				return fmt.Errorf("incomplete U3D texture %q", texture.Name)
+			}
+		}
+	}
+	return nil
+}

ofdgo_u3d_texture_decode.go

@@ -0,0 +1,281 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"image/png"
+	"io"
+
+	"golang.org/x/image/tiff"
+)
+
+// U3DTextureResolver 由调用方按原始URL读取外部纹理，地址解析、访问策略和读取限额由调用方控制
+// 返回的数据在本次绘制结束前不得修改；失败时尝试下一候选地址，取消及超时错误立即返回
+// 入参: ctx 取消上下文, url 绝对或相对地址
+// 返回: []byte 压缩图像数据, error 读取错误
+type U3DTextureResolver func(ctx context.Context, url string) ([]byte, error)
+
+// u3dImageReader 在图像解码器读取压缩数据时检查取消状态
+type u3dImageReader struct {
+	ctx  context.Context
+	data *bytes.Reader
+}
+
+// Read 读取顺序图像数据
+// 入参: p 接收缓冲
+// 返回: int 已读字节数, error 读取或取消错误
+func (r *u3dImageReader) Read(p []byte) (int, error) {
+	if err := r.ctx.Err(); err != nil {
+		return 0, err
+	}
+	return r.data.Read(p)
+}
+
+// ReadAt 读取指定偏移的图像数据
+// 入参: p 接收缓冲, offset 字节偏移
+// 返回: int 已读字节数, error 读取或取消错误
+func (r *u3dImageReader) ReadAt(p []byte, offset int64) (int, error) {
+	if err := r.ctx.Err(); err != nil {
+		return 0, err
+	}
+	return r.data.ReadAt(p, offset)
+}
+
+// texture 按需合成纹理并缓存，空名称使用ECMA-363第8.4.1节规定的默认纹理
+// 入参: name 纹理名称
+// 返回: *image.NRGBA64 非预乘纹理, error 资源、解码、预算或取消错误
+func (r *u3dRender) texture(name string) (*image.NRGBA64, error) {
+	if err := r.ctx.Err(); err != nil {
+		return nil, err
+	}
+	if cached := r.textures[name]; cached != nil {
+		return cached, nil
+	}
+	if err := r.reserve(1, 256); err != nil {
+		return nil, err
+	}
+	var pixels *image.NRGBA64
+	if name == "" {
+		if err := r.reserve(64, 8); err != nil {
+			return nil, err
+		}
+		pixels = image.NewNRGBA64(image.Rect(0, 0, 8, 8))
+		for y := range 8 {
+			for x := range 8 {
+				c := color.NRGBA64{65535, 65535, 65535, 65535}
+				if x/4 != y/4 {
+					c.G, c.B = 26214, 13107
+				}
+				pixels.SetNRGBA64(x, y, c)
+			}
+		}
+	} else {
+		index, exists := r.textureIndex[name]
+		if !exists {
+			return nil, fmt.Errorf("missing U3D texture %q", name)
+		}
+		var err error
+		pixels, err = r.decodeTexture(&r.model.Textures[index])
+		if err != nil {
+			return nil, fmt.Errorf("U3D texture %q: %w", name, err)
+		}
+	}
+	if r.textures == nil {
+		r.textures = make(map[string]*image.NRGBA64)
+	}
+	r.textures[name] = pixels
+	return pixels, nil
+}
+
+// decodeTexture 合成各续图像指定的通道，保留十六位颜色与非预乘透明度
+// 入参: texture 纹理资源
+// 返回: *image.NRGBA64 合成图像, error 格式、预算或取消错误
+func (r *u3dRender) decodeTexture(texture *U3DTexture) (*image.NRGBA64, error) {
+	switch texture.ImageType {
+	case 1, 14, 15, 16, 17:
+	default:
+		return nil, fmt.Errorf("invalid image type")
+	}
+	if texture.Width == 0 || texture.Height == 0 || len(texture.Images) == 0 || len(texture.Images) > 4 {
+		return nil, fmt.Errorf("invalid image dimensions or channel count")
+	}
+	var covered uint8
+	for _, source := range texture.Images {
+		if source.Compression < 1 || source.Compression > 4 {
+			return nil, fmt.Errorf("invalid image compression")
+		}
+		channels := u3dTextureChannels(source.Channels)
+		if source.Channels == 0 || source.Channels&^uint8(31) != 0 || channels&covered != 0 || channels&^u3dTextureChannels(texture.ImageType) != 0 {
+			return nil, fmt.Errorf("invalid image channels")
+		}
+		covered |= channels
+		if source.External && (r.resolveTexture == nil || len(source.URLs) == 0) {
+			return nil, fmt.Errorf("external texture image requires resolution")
+		}
+		if !source.External && uint64(len(source.Data)) != uint64(source.ByteCount) {
+			return nil, fmt.Errorf("invalid image data length")
+		}
+	}
+	if covered != u3dTextureChannels(texture.ImageType) {
+		return nil, fmt.Errorf("incomplete image channels")
+	}
+	if err := r.reserve(uint64(texture.Width)*uint64(texture.Height), 8); err != nil {
+		return nil, err
+	}
+	pixels := image.NewNRGBA64(image.Rect(0, 0, int(texture.Width), int(texture.Height)))
+	for y := range pixels.Rect.Dy() {
+		if err := r.ctx.Err(); err != nil {
+			return nil, err
+		}
+		for x := range pixels.Rect.Dx() {
+			if x%4096 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return nil, err
+				}
+			}
+			pixels.SetNRGBA64(x, y, color.NRGBA64{65535, 65535, 65535, 65535})
+		}
+	}
+	for _, source := range texture.Images {
+		if err := r.textureSource(pixels, source); err != nil {
+			return nil, err
+		}
+	}
+	return pixels, r.ctx.Err()
+}
+
+// textureSource 读取内置通道或按顺序尝试外部地址，不修改模型中的图像声明
+// 入参: pixels 目标纹理, source 通道图像
+// 返回: error 读取、解码、预算或取消错误
+func (r *u3dRender) textureSource(pixels *image.NRGBA64, source U3DTextureImage) error {
+	if !source.External {
+		return r.textureChannels(pixels, source)
+	}
+	if r.resolveTexture == nil || len(source.URLs) == 0 {
+		return fmt.Errorf("external texture image requires resolution")
+	}
+	var last error
+	for _, address := range source.URLs {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		data, err := r.resolveTexture(r.ctx, address)
+		if r.ctx.Err() != nil {
+			return r.ctx.Err()
+		}
+		if err == nil {
+			source.Data = data
+			err = r.textureChannels(pixels, source)
+			source.Data = nil
+		}
+		if canceled := r.ctx.Err(); canceled != nil {
+			return canceled
+		}
+		if err == nil || errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+			return err
+		}
+		last = fmt.Errorf("external texture image %q: %w", address, err)
+	}
+	return last
+}
+
+// textureChannels 解码并合成一幅续图像，临时预算包括像素、分块及压缩数据开销
+// 入参: pixels 目标纹理, source 通道图像
+// 返回: error 格式、预算或取消错误
+func (r *u3dRender) textureChannels(pixels *image.NRGBA64, source U3DTextureImage) error {
+	var config func(io.Reader) (image.Config, error)
+	var decode func(io.Reader) (image.Image, error)
+	switch source.Compression {
+	case 1, 3:
+		config, decode = jpeg.DecodeConfig, jpeg.Decode
+	case 2:
+		config, decode = png.DecodeConfig, png.Decode
+	case 4:
+		config, decode = tiff.DecodeConfig, tiff.Decode
+	default:
+		return fmt.Errorf("invalid image compression")
+	}
+	budget := r.remaining
+	defer func() { r.remaining = budget }()
+	if err := r.reserve(uint64(len(source.Data)), 4); err != nil {
+		return err
+	}
+	if err := r.reserve(1, 1<<20); err != nil {
+		return err
+	}
+	reader := &u3dImageReader{ctx: r.ctx, data: bytes.NewReader(source.Data)}
+	cfg, err := config(reader)
+	if err != nil {
+		return err
+	}
+	if cfg.Width != pixels.Rect.Dx() || cfg.Height != pixels.Rect.Dy() {
+		return fmt.Errorf("image dimensions differ from texture declaration")
+	}
+	if source.Compression == 3 && cfg.ColorModel != color.GrayModel || source.Compression == 1 && cfg.ColorModel != color.YCbCrModel {
+		return fmt.Errorf("invalid JPEG texture color model")
+	}
+	w, h := uint64(cfg.Width)+16, uint64(cfg.Height)+16
+	if source.Compression == 4 {
+		w, h = max(w, 1024), max(h, 1024)
+	}
+	if err := r.reserve(w*h, 32); err != nil {
+		return err
+	}
+	reader.data.Reset(source.Data)
+	img, err := decode(reader)
+	if err != nil {
+		return err
+	}
+	if img.Bounds() != pixels.Bounds() {
+		return fmt.Errorf("invalid decoded image dimensions")
+	}
+	channels := u3dTextureChannels(source.Channels)
+	grayAlpha := source.Channels == 1 && (cfg.ColorModel == color.GrayModel || cfg.ColorModel == color.Gray16Model)
+	for y := range cfg.Height {
+		for x := range cfg.Width {
+			if x%4096 == 0 {
+				if err := r.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			value := imageNRGBA64At(img, x, y)
+			current := pixels.NRGBA64At(x, y)
+			if channels&8 != 0 {
+				current.R = value.R
+			}
+			if channels&4 != 0 {
+				current.G = value.G
+			}
+			if channels&2 != 0 {
+				current.B = value.B
+			}
+			if channels&1 != 0 {
+				current.A = value.A
+				if grayAlpha {
+					current.A = value.R
+				}
+			}
+			pixels.SetNRGBA64(x, y, current)
+		}
+	}
+	return r.ctx.Err()
+}

ofdgo_u3d_triangle.go

@@ -20,10 +20,13 @@ import (
 	"slices"
 )
 
-// u3dVertex 保存裁剪前后的相机坐标及未预乘颜色
+// u3dVertex 保存裁剪前后的相机坐标、未预乘颜色及纹理插值输入
 type u3dVertex struct {
 	point           u3dVector
 	color           [4]float64
+	texture         [8][3]float64
+	textureMask     uint8
+	opacityOverride bool
 }
 
 // drawMesh 按实例复用顶点变换，着色列表按指定顺序绘制
@@ -51,8 +54,9 @@ func (r *u3dRender) drawMesh(instance u3dInstance, node *U3DNode, mesh *U3DMesh,
 		}
 		r.primitives = make(map[u3dPrimitiveKey]struct{})
 		defer func() {
-			r.remaining += 1024 + uint64(len(r.primitives))*512
+			r.remaining += 1024 + uint64(len(r.primitives))*512 + uint64(len(r.texturedPrimitives))*1024
 			r.primitives = nil
+			r.texturedPrimitives = nil
 		}()
 	}
 	normalCount := 0
@@ -161,15 +165,13 @@ func (r *u3dRender) drawMesh(instance u3dInstance, node *U3DNode, mesh *U3DMesh,
 					return err
 				}
 			}
-			style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, RenderPass: math.MaxUint32}}
+			style := u3dRenderStyle{shader: U3DShader{Blend: 0x606, RenderPass: r.shaderPass(name)}}
 			var err error
 			if shaded {
 				style, err = r.style(name)
 				if err != nil {
 					return err
 				}
-			} else if index, ok := r.shaders[name]; ok {
-				style.shader.RenderPass = r.model.Shaders[index].RenderPass
 			}
 			if style.shader.RenderPass&(1<<passIndex) == 0 {
 				continue
@@ -177,7 +179,23 @@ func (r *u3dRender) drawMesh(instance u3dInstance, node *U3DNode, mesh *U3DMesh,
 			if instance.opacity >= 0 || r.opacity >= 0 {
 				style.shader.Blend = 0x606
 			}
+			textures, err := r.shaderTextures(style.shader)
+			if err != nil {
+				return err
+			}
 			for i, corner := range face.Corners {
+				normal := faceNormal
+				if shaded && !mesh.ExcludeNormals && invertible {
+					normal = normals[corner.Normal]
+				}
+				if !front {
+					for j := range normal {
+						normal[j] = -normal[j]
+					}
+				}
+				if err := textures.coordinates(&vertices[i], mesh, shading, corner, normal); err != nil {
+					return err
+				}
 				if !shaded {
 					vertices[i].color = [4]float64{r.auxiliaryColor[0], r.auxiliaryColor[1], r.auxiliaryColor[2], 1}
 					if r.mode == U3DRenderIllustration {
@@ -192,15 +210,6 @@ func (r *u3dRender) drawMesh(instance u3dInstance, node *U3DNode, mesh *U3DMesh,
 					}
 					continue
 				}
-				normal := faceNormal
-				if !mesh.ExcludeNormals && invertible {
-					normal = normals[corner.Normal]
-				}
-				if !front {
-					for j := range normal {
-						normal[j] = -normal[j]
-					}
-				}
 				var diffuse, specular *[4]float32
 				if shading.Attributes&1 != 0 {
 					diffuse = &mesh.Diffuse[corner.Diffuse]
@@ -214,8 +223,9 @@ func (r *u3dRender) drawMesh(instance u3dInstance, node *U3DNode, mesh *U3DMesh,
 				}
 				if instance.opacity >= 0 {
 					vertices[i].color[3] = instance.opacity
+					vertices[i].opacityOverride = true
 				}
-				if r.opacity >= 0 {
+				if r.opacity >= 0 && textures == nil {
 					vertices[i].color[3] *= r.opacity
 				}
 			}
@@ -235,7 +245,7 @@ func (r *u3dRender) drawMesh(instance u3dInstance, node *U3DNode, mesh *U3DMesh,
 // 入参: triangle 三角面, shader 着色器, pass 绘制轮次
 // 返回: error 数值、资源或取消错误
 func (r *u3dRender) clipTriangle(triangle [3]u3dVertex, shader U3DShader, pass U3DViewPass) error {
-	if shader.Blend == 0x606 && triangle[0].color[3] == 0 && triangle[1].color[3] == 0 && triangle[2].color[3] == 0 {
+	if shader.Textures == ([8]*U3DTextureLayer{}) && shader.Blend == 0x606 && triangle[0].color[3] == 0 && triangle[1].color[3] == 0 && triangle[2].color[3] == 0 {
 		return r.ctx.Err()
 	}
 	var storage [2][12]u3dVertex
@@ -259,13 +269,7 @@ func (r *u3dRender) clipTriangle(triangle [3]u3dVertex, shader U3DShader, pass U
 			}
 			if (d >= 0) != (previousDistance >= 0) {
 				t := u3dClipFraction(previousDistance, d)
-				var intersection u3dVertex
+				intersection := u3dInterpolate(previous, vertex, t)
-				for i := range intersection.point {
-					intersection.point[i] = previous.point[i]*(1-t) + vertex.point[i]*t
-				}
-				for i := range intersection.color {
-					intersection.color[i] = previous.color[i]*(1-t) + vertex.color[i]*t
-				}
 				if output == len(storage[next]) {
 					return fmt.Errorf("invalid U3D clipped polygon")
 				}
@@ -298,6 +302,10 @@ func (r *u3dRender) clipTriangle(triangle [3]u3dVertex, shader U3DShader, pass U
 // 入参: triangle 已裁剪三角面, shader 着色器, pass 绘制轮次
 // 返回: error 数值、预算或取消错误
 func (r *u3dRender) rasterTriangle(triangle [3]u3dVertex, shader U3DShader, pass U3DViewPass) error {
+	textures, err := r.shaderTextures(shader)
+	if err != nil {
+		return err
+	}
 	var x, y, reciprocal [3]float64
 	for i, v := range triangle {
 		reciprocal[i] = 1
@@ -385,13 +393,27 @@ func (r *u3dRender) rasterTriangle(triangle [3]u3dVertex, shader U3DShader, pass
 				color[c] = triangle[0].color[c] + w1*(triangle[1].color[c]-triangle[0].color[c]) + w2*(triangle[2].color[c]-triangle[0].color[c])
 			}
 			position := u3dVector{}
-			if pass.Attributes&1 != 0 {
+			if pass.Attributes&1 != 0 || textures != nil && textures.reflection {
 				position = u3dVector{(px - r.viewport[0] - r.viewport[2]/2 - r.camera.ShiftX) / r.camera.ScaleX, (r.viewport[1] + r.viewport[3]/2 + r.camera.ShiftY - py) / r.camera.ScaleY, depth}
 				if r.camera.Perspective {
 					position[0] *= depth
 					position[1] *= depth
 				}
 			}
+			if textures != nil {
+				var uv [8][3]float64
+				for layer := range textures.layers {
+					if textures.mask&(1<<layer) == 0 {
+						continue
+					}
+					for c := range uv[layer] {
+						uv[layer][c] = triangle[0].texture[layer][c] + w1*(triangle[1].texture[layer][c]-triangle[0].texture[layer][c]) + w2*(triangle[2].texture[layer][c]-triangle[0].texture[layer][c])
+					}
+				}
+				if err := r.textureColor(textures, &color, &uv, position, triangle[0].opacityOverride); err != nil {
+					return err
+				}
+			}
 			visible, err := u3dFragmentColor(&color, position, &shader, &pass)
 			if err != nil {
 				return err

ofdgo_u3d_view_render.go

@@ -0,0 +1,103 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"image"
+	"math"
+)
+
+// viewLayers 按ECMA-363第9.5.4节依次绘制背景层或覆盖层
+// 入参: layers 按后至前排列的纹理层
+// 返回: error 参数、资源、预算或取消错误
+func (r *u3dRender) viewLayers(layers []U3DViewLayer) error {
+	for _, layer := range layers {
+		if err := r.ctx.Err(); err != nil {
+			return err
+		}
+		for _, value := range [...]float32{layer.Blend, layer.Rotation, layer.Location[0], layer.Location[1], layer.Scale[0], layer.Scale[1]} {
+			if !finite(float64(value)) {
+				return fmt.Errorf("invalid U3D view layer values")
+			}
+		}
+		texture, err := r.texture(layer.Texture)
+		if err != nil {
+			return err
+		}
+		blend := min(1, max(0, float64(layer.Blend)))
+		if blend == 0 || layer.Scale[0] == 0 || layer.Scale[1] == 0 {
+			continue
+		}
+		sin, cos := math.Sincos(float64(layer.Rotation))
+		x, y := float64(layer.Location[0]), float64(layer.Location[1])
+		if r.view.Attributes&1 != 0 {
+			x *= float64(r.output.Rect.Dx())
+			y *= float64(r.output.Rect.Dy())
+		}
+		sx, sy := float64(layer.Scale[0]), float64(layer.Scale[1])
+		rx, ry := float64(layer.Registration[0]), float64(layer.Registration[1])
+		m := RasterMatrix{cos * sx, -sin * sx, sin * sy, cos * sy, x - cos*sx*rx - sin*sy*ry, y + sin*sx*rx - cos*sy*ry}
+		bounds := rasterImageBounds(texture.Bounds(), m, r.output.Bounds())
+		for py := bounds.Min.Y; py < bounds.Max.Y; py++ {
+			for px := bounds.Min.X; px < bounds.Max.X; px++ {
+				if px%4096 == 0 || px == bounds.Min.X {
+					if err := r.ctx.Err(); err != nil {
+						return err
+					}
+				}
+				cx, cy := float64(px)+.5, float64(py)+.5
+				if cx < r.viewport[0] || cy < r.viewport[1] || cx >= r.viewport[0]+r.viewport[2] || cy >= r.viewport[1]+r.viewport[3] {
+					continue
+				}
+				dx, dy := cx-x, cy-y
+				u, v := (cos*dx-sin*dy)/sx+rx, (sin*dx+cos*dy)/sy+ry
+				if u < 0 || v < 0 || u >= float64(texture.Rect.Dx()) || v >= float64(texture.Rect.Dy()) {
+					continue
+				}
+				value := u3dTextureSample(texture, u, v)
+				pixel := &r.frame[py*r.output.Rect.Dx()+px]
+				alpha := value[3] * blend
+				for i := range pixel.color {
+					pixel.color[i] = value[i]*blend + pixel.color[i]*(1-alpha)
+				}
+			}
+		}
+	}
+	return r.ctx.Err()
+}
+
+// u3dTextureSample 在像素中心进行双线性采样，使用预乘颜色避免透明边缘色晕
+// 入参: texture 纹理, x 横向像素坐标, y 纵向像素坐标
+// 返回: [4]float64 预乘颜色及透明度
+func u3dTextureSample(texture *image.NRGBA64, x, y float64) [4]float64 {
+	x, y = x-.5, y-.5
+	x0, y0 := int(math.Floor(x)), int(math.Floor(y))
+	fx, fy := x-float64(x0), y-float64(y0)
+	wx, wy := [2]float64{1 - fx, fx}, [2]float64{1 - fy, fy}
+	var result [4]float64
+	for row := range 2 {
+		for col := range 2 {
+			weight := wx[col] * wy[row]
+			c := texture.NRGBA64At(min(max(0, x0+col), texture.Rect.Max.X-1), min(max(0, y0+row), texture.Rect.Max.Y-1))
+			alpha := float64(c.A) / 65535
+			result[0] += float64(c.R) / 65535 * alpha * weight
+			result[1] += float64(c.G) / 65535 * alpha * weight
+			result[2] += float64(c.B) / 65535 * alpha * weight
+			result[3] += alpha * weight
+		}
+	}
+	return result
+}

ofdgo_u3d_weights.go

@@ -0,0 +1,180 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"math"
+)
+
+// U3DBoneWeight 保存某骨骼对一个位置的影响系数
+type U3DBoneWeight struct {
+	Bone   uint32
+	Weight float32
+}
+
+// U3DBoneWeights 保存修饰链中的权重，Index为链内位置，Attributes的1、2、4分别表示网格、线集、点集
+// 第i个位置的权重为Weights[Offsets[i]:Offsets[i+1]]，空区间表示没有骨骼影响
+type U3DBoneWeights struct {
+	Index, Attributes   uint32
+	InverseQuantization float32
+	Offsets             []uint32
+	Weights             []U3DBoneWeight
+}
+
+// boneWeights 读取ECMA-363第9.7.4节权重修饰器，末项权重由其余各项之和确定
+// 入参: values 字段读取器, name 所属链名, chain 链类型, index 链内位置
+// 返回: error 结构、数值、预算或取消错误
+func (d *u3dDecoder) boneWeights(values *u3dValues, name string, chain int, index uint32) error {
+	r := u3dResourceReader{values: values, decoder: d}
+	defer r.release()
+	weights := U3DBoneWeights{Index: index, Attributes: r.u32(), InverseQuantization: r.f32()}
+	positions := r.u32()
+	if err := r.err(); err != nil {
+		return err
+	}
+	if weights.Attributes != 1 && weights.Attributes != 2 && weights.Attributes != 4 || weights.InverseQuantization < 0 {
+		return fmt.Errorf("invalid U3D bone weight parameters")
+	}
+	if err := d.reserve(uint64(positions)+1, 4); err != nil {
+		return err
+	}
+	weights.Offsets = make([]uint32, int(positions)+1)
+	for position := range positions {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		count := r.value(0, false)
+		if err := r.err(); err != nil {
+			return err
+		}
+		start := len(weights.Weights)
+		needed := uint64(start) + uint64(count)
+		if needed > math.MaxUint32 {
+			return fmt.Errorf("U3D bone weight count exceeds limit")
+		}
+		if needed > uint64(cap(weights.Weights)) {
+			capacity := max(needed, uint64(cap(weights.Weights))*2)
+			if err := d.reserve(capacity, 8); err != nil {
+				return err
+			}
+			grown := make([]U3DBoneWeight, int(needed), int(capacity))
+			copy(grown, weights.Weights)
+			d.remaining += uint64(cap(weights.Weights)) * 8
+			weights.Weights = grown
+		} else {
+			weights.Weights = weights.Weights[:int(needed)]
+		}
+		list := weights.Weights[start:]
+		for i := range list {
+			if i%256 == 0 {
+				if err := d.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			list[i].Bone = r.value(1, false)
+			if err := r.err(); err != nil {
+				return err
+			}
+		}
+		var total float32
+		for i := 0; i+1 < len(list); i++ {
+			if i%256 == 0 {
+				if err := d.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			list[i].Weight = float32(float64(r.value(2, false)) * float64(weights.InverseQuantization))
+			total += list[i].Weight
+			if err := r.err(); err != nil {
+				return err
+			}
+			if !finite(float64(total)) || total > 1 {
+				return fmt.Errorf("invalid U3D bone weight sum")
+			}
+		}
+		if len(list) != 0 {
+			list[len(list)-1].Weight = 1 - total
+		}
+		weights.Offsets[position+1] = uint32(needed)
+	}
+	if err := r.done(); err != nil {
+		return err
+	}
+	if chain == 1 {
+		d.meshes[name].mesh.BoneWeights = append(d.meshes[name].mesh.BoneWeights, weights)
+	} else {
+		node := &d.model.Nodes[d.nodes[name]]
+		node.BoneWeights = append(node.BoneWeights, weights)
+	}
+	return nil
+}
+
+// checkBoneWeights 在几何和节点声明齐备后校验权重引用，允许节点引用后续资源
+// 返回: error 位置、骨骼引用或取消错误
+func (d *u3dDecoder) checkBoneWeights() error {
+	for _, name := range d.meshOrder {
+		mesh := d.meshes[name]
+		if err := d.checkMeshBoneWeights(mesh, mesh.mesh.BoneWeights); err != nil {
+			return err
+		}
+	}
+	for _, node := range d.model.Nodes {
+		if err := d.checkMeshBoneWeights(d.meshes[node.Resource], node.BoneWeights); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// checkMeshBoneWeights 校验适用于指定几何类型的权重，不把未匹配的类型强加到几何上
+// 入参: mesh 几何声明，可为空, sets 权重修饰器
+// 返回: error 位置、骨骼引用或取消错误
+func (d *u3dDecoder) checkMeshBoneWeights(mesh *u3dMeshDeclaration, sets []U3DBoneWeights) error {
+	for _, weights := range sets {
+		if err := d.ctx.Err(); err != nil {
+			return err
+		}
+		if mesh == nil {
+			if len(weights.Weights) != 0 {
+				return fmt.Errorf("missing U3D bone weight geometry")
+			}
+			continue
+		}
+		kind := uint32(1)
+		if mesh.points {
+			kind = 4
+		} else if mesh.line != nil {
+			kind = 2
+		}
+		if weights.Attributes != kind {
+			continue
+		}
+		if uint64(len(weights.Offsets)-1) > uint64(len(mesh.mesh.Positions)) {
+			return fmt.Errorf("invalid U3D bone weight position count")
+		}
+		for index, weight := range weights.Weights {
+			if index%1024 == 0 {
+				if err := d.ctx.Err(); err != nil {
+					return err
+				}
+			}
+			if uint64(weight.Bone) >= uint64(len(mesh.mesh.Bones)) {
+				return fmt.Errorf("invalid U3D bone weight index")
+			}
+		}
+	}
+	return nil
+}

ofdgo_version_edit.go

@@ -84,7 +84,7 @@ func (r *Reader) versionFileDependencies(ctx context.Context, entry string, part
 
 // versionEditGraph 沿标准文件引用建立版本依赖图，二进制资源只记录路径
 // 入参: ctx 取消上下文, entry 文档入口, parts 待修改条目, generated 本次自产页面及引用
-// 返回: *versionEditGraph 依赖图, error 读取或结构错误
+// 返回: *versionEditGraph 依赖图, error 读取、结构或取消错误
 func (r *Reader) versionEditGraph(ctx context.Context, entry string, parts map[string][]byte, generated map[string]editorGeneratedReferences) (*versionEditGraph, error) {
 	graph := &versionEditGraph{files: make(map[string]*versionEditFile), used: make(map[string]bool)}
 	queue := []string{entry}
@@ -104,12 +104,12 @@ func (r *Reader) versionEditGraph(ctx context.Context, entry string, parts map[s
 		}
 		if !ok {
 			var err error
-			data, err = r.readFile(name)
+			data, err = r.readFileViewContext(ctx, name)
 			if err != nil {
 				return nil, err
 			}
 		}
-		root, err := parseEditorXML(data)
+		root, err := parseEditorXMLContext(ctx, data)
 		if err != nil {
 			return nil, fmt.Errorf("version file %s: %w", name, err)
 		}
@@ -119,17 +119,20 @@ func (r *Reader) versionEditGraph(ctx context.Context, entry string, parts map[s
 		if root.name.Local == "Res" {
 			base = root.attr("BaseLoc")
 		}
-		var visit func(*editorXML)
+		var visit func(*editorXML) error
-		visit = func(node *editorXML) {
+		visit = func(node *editorXML) error {
+			if err := ctx.Err(); err != nil {
+				return err
+			}
 			if node != root && !node.matchesOFD(node.name.Local) {
-				return
+				return nil
 			}
 			parent := ""
 			if node.parent != nil {
 				parent = node.parent.name.Local
 			}
 			if parent == "Extension" && node.name.Local == "Data" {
-				return
+				return nil
 			}
 			add := func(attribute, value string, kind int) {
 				if strings.TrimSpace(value) == "" {
@@ -154,10 +157,18 @@ func (r *Reader) versionEditGraph(ctx context.Context, entry string, parts map[s
 				}
 			}
 			for _, child := range node.children {
-				visit(child)
+				if err := visit(child); err != nil {
+					return err
 				}
 			}
-		visit(root)
+			return nil
+		}
+		if err := visit(root); err != nil {
+			return nil, err
+		}
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
 	}
 	return graph, nil
 }
@@ -408,7 +419,7 @@ func (r *Reader) versionOutputChanges(ctx context.Context, changes map[string][]
 
 // rewrite 更新已隔离文件的引用，保留其余XML及相对路径基准
 // 入参: paths 原路径到新路径的映射
-// 返回: []byte 更新后的XML, error 属性编码错误
+// 返回: []byte 更新后的XML，未改动时借用原文, error 属性编码错误
 func (file *versionEditFile) rewrite(paths map[string]string) ([]byte, error) {
 	var patches []editorXMLPatch
 	headers := make(map[*editorXML][]versionEditLink)
@@ -444,6 +455,9 @@ func (file *versionEditFile) rewrite(paths map[string]string) ([]byte, error) {
 			patches = append(patches, editorXMLPatch{node.start, node.open, data[:root.open]})
 		}
 	}
+	if len(patches) == 0 {
+		return file.data, nil
+	}
 	return editorPatchXML(file.data, patches), nil
 }
 

ofdgo_writer.go

@@ -441,8 +441,8 @@ func (e *Editor) writePartsWithPages(write func(string, []byte, bool) error, pro
 	return nil
 }
 
-// usedResources 筛选当前引用的新增资源及需要跨页复用的原资源文件，不修改资源池
+// usedResources 沿图层、对象及资源依赖筛选新增资源和共享文件，不修改资源池
-// 返回: []editorResource 新增字体, []editorResource 新增图片, []ColorSpace 新增颜色空间, []string 原资源文件
+// 返回: []editorResource 新增字体, []editorResource 新增图片, []ColorSpace 新增颜色空间, []string 独立资源文件
 func (e *Editor) usedResources() (fonts, images []editorResource, spaces []ColorSpace, sourceFiles []string) {
 	used := make(map[string]bool)
 	promoted := make(map[string]bool)
@@ -487,10 +487,13 @@ func (e *Editor) usedResources() (fonts, images []editorResource, spaces []Color
 	for _, page := range e.pages {
 		collectActionReferences(page.Actions, used)
 		var original map[string]GraphicObject
+		var originalLayers map[string]string
 		if e.source != nil {
 			original = make(map[string]GraphicObject)
+			originalLayers = make(map[string]string)
 			if source := e.source.pages[page.ID]; source != nil && source.original != nil {
 				for _, layer := range source.original.Content.Layer {
+					originalLayers[layer.ID] = layer.DrawParam
 					for _, object := range layer.Objects {
 						original[editorObjectID(object)] = object
 					}
@@ -498,6 +501,12 @@ func (e *Editor) usedResources() (fonts, images []editorResource, spaces []Color
 			}
 		}
 		for _, layer := range page.Content.Layer {
+			if layer.DrawParam != "" {
+				used[layer.DrawParam] = true
+				if e.source != nil && originalLayers[layer.ID] != layer.DrawParam {
+					promoted[layer.DrawParam] = true
+				}
+			}
 			for _, object := range layer.Objects {
 				before, exists := original[editorObjectID(object)]
 				collectObjectReferences(object, used)
@@ -514,16 +523,33 @@ func (e *Editor) usedResources() (fonts, images []editorResource, spaces []Color
 	}
 	normalizeResourceReferences(used)
 	normalizeResourceReferences(promoted)
-	for i := len(e.resources) - 1; i >= 0; i-- {
+	definitions := make(map[string]int)
-		resource := e.resources[i]
+	var pending []string
-		if resource.definition() != "" && used[resource.definition()] {
+	for index, resource := range e.resources {
-			for _, id := range resource.references {
+		if id := resource.definition(); id != "" {
-				used[id] = true
+			definitions[id] = index
-				if e.source != nil {
+			if used[id] {
-					promoted[id] = true
+				pending = append(pending, id)
 			}
 		}
 	}
+	for len(pending) != 0 {
+		id := pending[len(pending)-1]
+		pending = pending[:len(pending)-1]
+		index, ok := definitions[id]
+		if !ok {
+			continue
+		}
+		delete(definitions, id)
+		for _, reference := range e.resources[index].references {
+			used[reference] = true
+			if e.source != nil {
+				promoted[reference] = true
+			}
+			if _, ok := definitions[reference]; ok {
+				pending = append(pending, reference)
+			}
+		}
 	}
 	for _, resource := range e.resources {
 		if resource.definition() != "" && used[resource.definition()] {