Changes

src/lib/convertToGLB.ts

@@ -0,0 +1,67 @@
+import * as THREE from 'three';
+import { STLLoader } from 'three/examples/jsm/loaders/STLLoader.js';
+import { OBJLoader } from 'three/examples/jsm/loaders/OBJLoader.js';
+import { GLTFExporter } from 'three/examples/jsm/exporters/GLTFExporter.js';
+
+type SupportedExt = 'glb' | 'obj' | 'stl';
+
+export function getSupportedExtension(fileName: string): SupportedExt | null {
+  const ext = fileName.split('.').pop()?.toLowerCase();
+  if (ext === 'glb' || ext === 'obj' || ext === 'stl') return ext;
+  return null;
+}
+
+export const ACCEPTED_EXTENSIONS = '.glb,.obj,.stl';
+
+/**
+ * Convert an OBJ or STL file (ArrayBuffer) into a GLB Blob.
+ * GLB files are returned as-is from their original blob.
+ */
+export async function convertToGLB(
+  buffer: ArrayBuffer,
+  ext: 'obj' | 'stl',
+  fileName: string
+): Promise<{ blob: Blob; fileName: string; fileSize: number }> {
+  const scene = new THREE.Scene();
+
+  const material = new THREE.MeshStandardMaterial({
+    color: 0x8899aa,
+    metalness: 0.85,
+    roughness: 0.35,
+  });
+
+  if (ext === 'stl') {
+    const loader = new STLLoader();
+    const geometry = loader.parse(buffer);
+    geometry.computeVertexNormals();
+    const mesh = new THREE.Mesh(geometry, material);
+    mesh.name = fileName.replace(/\.stl$/i, '');
+    scene.add(mesh);
+  } else {
+    const loader = new OBJLoader();
+    const text = new TextDecoder().decode(buffer);
+    const obj = loader.parse(text);
+    obj.traverse((child) => {
+      if (child instanceof THREE.Mesh) {
+        child.material = material;
+      }
+    });
+    obj.name = fileName.replace(/\.obj$/i, '');
+    scene.add(obj);
+  }
+
+  const exporter = new GLTFExporter();
+  const glb = await new Promise<ArrayBuffer>((resolve, reject) => {
+    exporter.parse(
+      scene,
+      (result) => resolve(result as ArrayBuffer),
+      (error) => reject(error),
+      { binary: true }
+    );
+  });
+
+  const glbFileName = fileName.replace(/\.(obj|stl)$/i, '.glb');
+  const blob = new Blob([glb], { type: 'model/gltf-binary' });
+
+  return { blob, fileName: glbFileName, fileSize: blob.size };
+}