fix:3的模型动态修改模型文件

examples/flutter/animations/lib/main.dart

@@ -1,10 +1,13 @@
+import 'dart:convert';
 import 'dart:io';
 
 import 'package:animations/utils/binary_manager.dart';
 import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
+import 'package:path/path.dart' as p;
+import 'package:path_provider/path_provider.dart';
 
-import 'model_viewer.dart';
+import 'cup.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -31,7 +34,7 @@ class MyApp extends StatelessWidget {
         primarySwatch: Colors.blue,
         visualDensity: VisualDensity.adaptivePlatformDensity,
       ),
-      home: const ModelViewerWithTextureReplace(),
+      home: ModelViewerWithTextureReplace(),
     );
   }
 }
@@ -52,11 +55,11 @@ class _ModelViewerWithTextureReplaceState
   int _keyValue = 0;
   String _statusMessage = "正在加载模型...";
   bool _isReplacingTexture = false;
+  File? _selectedImage;
 
   @override
   void initState() {
     super.initState();
-    BinaryManager.readLocalJson();
     _load3DModels();
     // _loadModel();
   }
@@ -117,69 +120,101 @@ class _ModelViewerWithTextureReplaceState
     });
 
     try {
-      // 使用FilePicker选择文件
+      // 选择图片文件
       FilePickerResult? result = await FilePicker.platform.pickFiles(
         type: FileType.image,
         allowMultiple: false,
       );
 
-      if (result != null &&
-          result.files.isNotEmpty &&
-          result.files.single.path != null) {
-        setState(() {
-          _statusMessage = "正在应用新纹理...";
-        });
-
-        // 获取选中的文件
-        PlatformFile file = result.files.first;
-        File newTexture = File(file.path!);
-
-        // 检查文件是否存在
-        if (await newTexture.exists()) {
-          // 先备份旧纹理文件（可选）
-          final backupTexturePath = '${_texturePath!}.backup';
-          final oldTexture = File(_texturePath!);
-          if (await oldTexture.exists()) {
-            await oldTexture.copy(backupTexturePath);
-          }
-
-          // 复制选中的图片到纹理路径
-          await newTexture.copy(_texturePath!);
-
-          // 给渲染器一点时间来处理文件变化
-          await Future.delayed(const Duration(milliseconds: 3000));
-
-          Navigator.push(
-            context,
-            MaterialPageRoute(
-              builder: (context) => LocalModelViewer(),
-            ),
-          );
-
-          // // 强制重建ViewerWidget以应用新纹理
-          // setState(() {
-          //   _keyValue++;
-          //   _statusMessage = "纹理已更新";
-          // });
-
-          // ScaffoldMessenger.of(context).showSnackBar(
-          //   const SnackBar(content: Text('纹理已成功更新')),
-          // );
-        } else {
-          setState(() {
-            _statusMessage = "文件不存在";
-          });
-        }
-      } else {
+      if (result == null ||
+          result.files.isEmpty ||
+          result.files.single.path == null) {
         setState(() {
           _statusMessage = "取消选择";
         });
+        return;
+      }
+      _selectedImage = File(result.files.single.path!);
+
+      final selectedFile = result.files.single;
+      final fileExtension = p.extension(selectedFile.path!).toLowerCase();
+
+      // 可选：仅允许特定图片格式
+      if (!['.jpg', '.jpeg', '.png'].contains(fileExtension)) {
+        setState(() {
+          _statusMessage = "仅支持 JPG / PNG 格式纹理";
+        });
+        return;
+      }
+
+      final newTexture = File(selectedFile.path!);
+      final supportDir = await getApplicationSupportDirectory();
+      final modelDir = p.join(supportDir.path, 'cup');
+      final modelPath = p.join(modelDir, 'model.gltf');
+      final modelFile = File(modelPath);
+
+      if (!await newTexture.exists()) {
+        setState(() {
+          _statusMessage = "所选纹理文件不存在";
+        });
+        return;
+      }
+
+      // 复制新纹理为固定名 new.jpg 到模型目录
+      final newTexturePath = p.join(modelDir, 'new.jpg');
+      await newTexture.copy(newTexturePath);
+      _texturePath = newTexturePath;
+
+      // 修改 GLTF 文件
+      if (await modelFile.exists()) {
+        String gltfContent = await modelFile.readAsString();
+
+        // ✅ 修复 GLTF 中非法负号格式（例如 "- 0.123" => "-0.123"）
+        gltfContent = gltfContent.replaceAllMapped(
+          RegExp(r'-\s+(\d+(\.\d+)?)'),
+          (match) => '-${match.group(1)}',
+        );
+
+        final gltfJson = jsonDecode(gltfContent);
+
+        // 安全修改 images[0].uri
+        if (gltfJson['images'] != null && gltfJson['images'].isNotEmpty) {
+          gltfJson['images'][0]['uri'] = './new.jpg';
+        }
+
+        // 可选：修改 textures[0].name
+        if (gltfJson['textures'] != null && gltfJson['textures'].isNotEmpty) {
+          gltfJson['textures'][0]['name'] = 'new.jpg';
+        }
+
+        // 写回更新后的内容
+        final updatedContent =
+            const JsonEncoder.withIndent('  ').convert(gltfJson);
+        await modelFile.writeAsString(updatedContent);
+
+        print('GLTF文件已成功更新');
+
+        // 重建模型视图
+        setState(() {
+          _keyValue++;
+          _statusMessage = "纹理已更新为 new.jpg";
+        });
+
+        ScaffoldMessenger.of(context).showSnackBar(
+          const SnackBar(content: Text('纹理已成功更新为 new.jpg')),
+        );
+      } else {
+        print('GLTF文件不存在: $modelPath');
+        setState(() {
+          _statusMessage = "GLTF文件不存在";
+        });
       }
     } catch (e) {
       print('更换纹理失败: $e');
       setState(() {
         _statusMessage = "更换纹理失败: $e";
       });
+
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(content: Text('更换纹理失败: $e')),
       );
@@ -192,6 +227,15 @@ class _ModelViewerWithTextureReplaceState
 
   // 重置纹理到原始状态
   Future<void> _resetTexture() async {
+    Navigator.push(
+      context,
+      MaterialPageRoute(
+        builder: (context) => Cup(),
+        // builder: (context) => CupPage(),
+      ),
+    );
+    return;
+
     if (_isReplacingTexture || _texturePath == null) return;
 
     setState(() {
@@ -285,6 +329,22 @@ class _ModelViewerWithTextureReplaceState
                 )
               : Column(
                   children: [
+                    if (_selectedImage != null)
+                      Container(
+                        width: 300,
+                        height: 300,
+                        decoration: BoxDecoration(
+                          border: Border.all(color: Colors.blue, width: 2),
+                          borderRadius: BorderRadius.circular(12),
+                        ),
+                        child: ClipRRect(
+                          borderRadius: BorderRadius.circular(10),
+                          child: Image.file(
+                            _selectedImage!,
+                            fit: BoxFit.cover,
+                          ),
+                        ),
+                      ),
                     // Expanded(
                     //   child: ViewerWidget(
                     //     key: ValueKey(_keyValue),
@@ -317,21 +377,10 @@ class _ModelViewerWithTextureReplaceState
                               ),
                               ElevatedButton.icon(
                                 icon: const Icon(Icons.refresh),
-                                label: const Text('重置纹理'),
+                                label: const Text('3d查看'),
                                 onPressed:
                                     _isReplacingTexture ? null : _resetTexture,
                               ),
-                              ElevatedButton.icon(
-                                icon: const Icon(Icons.camera),
-                                label: const Text('重置视图'),
-                                onPressed: _isReplacingTexture
-                                    ? null
-                                    : () {
-                                        setState(() {
-                                          _keyValue++;
-                                        });
-                                      },
-                              ),
                             ],
                           ),
                           const SizedBox(height: 8),