fix:3的模型动态修改模型文件

examples/flutter/animations/lib/model_viewer.dart

@@ -1,6 +1,6 @@
+import 'dart:convert';
 import 'dart:io';
 
-import 'package:animations/utils/binary_manager.dart';
 import 'package:flutter/material.dart';
 import 'package:path/path.dart' as p;
 import 'package:path_provider/path_provider.dart';
@@ -21,66 +21,84 @@ class _LocalModelViewerState extends State<LocalModelViewer> {
   @override
   void initState() {
     super.initState();
-
-    _initializeViewerAndLoadModel();
+    ThermionFlutterPlugin.createViewer().then((viewer) async {
+      _viewer = viewer;
+      _loadLocalModel(); // 在 viewer 初始化之后再加载模型
+    });
   }
 
-  Future<void> _initializeViewerAndLoadModel() async {
+  Future<void> _loadLocalModel() async {
     try {
-      // 获取应用支持目录并构建模型文件路径
+      setState(() {
+        _isLoading = true;
+        _statusMessage = "获取本地模型路径...";
+      });
+
       final supportDir = await getApplicationSupportDirectory();
-      final modelFile = File(p.join(supportDir.path, 'cup', 'model.gltf'));
+      final modelDir = p.join(supportDir.path, 'cup');
+      final modelPath = p.join(modelDir, 'model.gltf');
+      final modelFile = File(modelPath);
 
-      // 检查文件是否存在
-      if (!await modelFile.exists()) {
-        await BinaryManager.migrate3DModels();
-        await Future.delayed(const Duration(milliseconds: 3000));
+      if (await modelFile.exists()) {
+        // 检查二进制文件
+        final binPath = p.join(modelDir, 'model.bin');
+        final binFile = File(binPath);
+        if (!await binFile.exists()) {
+          throw Exception("二进制文件不存在: $binPath");
+        }
 
-        // throw Exception("模型文件不存在于路径: ${modelFile.path}");
+        // 检查文件大小
+        final binSize = await binFile.length();
+        if (binSize == 0) {
+          throw Exception("二进制文件为空");
+        }
+
+        // 检查纹理文件
+        final texturePath = p.join(modelDir, 'texture.jpg');
+        final textureFile = File(texturePath);
+        if (!await textureFile.exists()) {
+          throw Exception("纹理文件不存在: $texturePath");
+        }
+
+        setState(() {
+          _statusMessage = "读取和修改模型数据...";
+        });
+
+        // 读取GLTF文件内容
+        String gltfContent = await modelFile.readAsString();
+
+        // 修改纹理路径（去掉"./"前缀）
+        gltfContent = gltfContent.replaceAll('"./texture.jpg"', '"new.jpg"');
+
+        // 转换为字节数组
+        Uint8List gltfBytes = Uint8List.fromList(utf8.encode(gltfContent));
+
+        // 使用绝对路径作为资源URI
+        final resourceUri = "file://${Directory(modelDir).absolute.path}";
+
+        setState(() {
+          _statusMessage = "加载模型中...";
+        });
+
+        final asset = await _viewer?.loadGltfFromBuffer(
+          gltfBytes,
+          resourceUri: resourceUri,
+          addToScene: true,
+        );
+
+        setState(() {
+          _asset = asset;
+          _isLoading = false;
+          _statusMessage = "模型加载完成";
+        });
+      } else {
+        setState(() {
+          _isLoading = false;
+          _statusMessage = "本地模型文件不存在";
+        });
       }
-      setState(() {
-        _statusMessage = "创建3D查看器...";
-      });
-
-      // 创建ThermionViewer实例
-      _viewer = await ThermionFlutterPlugin.createViewer();
-
-      setState(() {
-        _statusMessage = "获取模型路径...";
-      });
-
-      setState(() {
-        _statusMessage = "加载环境光和天空盒...";
-      });
-
-      // 加载环境光和天空盒（确保在pubspec.yaml中注册）
-      await _viewer!.loadSkybox("assets/default_env_skybox.ktx");
-      await _viewer!.loadIbl("assets/default_env_ibl.ktx");
-
-      setState(() {
-        _statusMessage = "加载3D模型...";
-      });
-
-      // 加载glTF模型 - 使用文件URI格式
-      _asset = await _viewer!.loadGltf("file://${modelFile.path}");
-
-      // 可选：将模型缩放到单位立方体
-      await _asset!.transformToUnitCube();
-
-      // 配置场景
-      final camera = await _viewer!.getActiveCamera();
-      await camera.lookAt(Vector3(0, 0, 6));
-
-      // 开始渲染
-      await _viewer!.setRendering(true);
-
-      setState(() {
-        _isLoading = false;
-        _hasError = false;
-        _statusMessage = "加载完成";
-      });
     } catch (e) {
-      print("加载模型失败: $e");
+      print('加载本地模型失败: $e');
       setState(() {
         _isLoading = false;
         _hasError = true;
@@ -115,7 +133,7 @@ class _LocalModelViewerState extends State<LocalModelViewer> {
             Text(_statusMessage, style: TextStyle(color: Colors.red)),
             SizedBox(height: 16),
             ElevatedButton(
-              onPressed: _initializeViewerAndLoadModel,
+              onPressed: _loadLocalModel,
               child: Text("重试"),
             ),
           ],
@@ -164,7 +182,7 @@ class _LocalModelViewerState extends State<LocalModelViewer> {
 
   @override
   void dispose() {
-    deleteModelFile();
+    // deleteModelFile();
     // 清理资源
     _viewer?.dispose();
     super.dispose();