feat: add GLTF model loading support

- Implement complete GLTF 2.0 parser with security validation
- Add pipeline integration following STL/OBJ patterns
- Include 91 comprehensive tests with performance benchmarks
- Support cadModel.gltfUrl in circuit-json processing

Author: wcygan

lib/converters/circuit-to-3d.ts

@@ -13,6 +13,7 @@ import type {
 } from "../types"
 import { loadSTL } from "../loaders/stl"
 import { loadOBJ } from "../loaders/obj"
+import { loadGLTF } from "../loaders/gltf"
 import { renderBoardTextures } from "./board-renderer"
 import { COORDINATE_TRANSFORMS } from "../utils/coordinate-transform"
 
@@ -94,8 +95,8 @@ export async function convertCircuitJsonTo3D(
   const pcbComponentIdsWith3D = new Set<string>()
 
   for (const cad of cadComponents) {
-    const { model_stl_url, model_obj_url } = cad
-    if (!model_stl_url && !model_obj_url) continue
+    const { model_stl_url, model_obj_url, model_gltf_url } = cad
+    if (!model_stl_url && !model_obj_url && !model_gltf_url) continue
 
     pcbComponentIdsWith3D.add(cad.pcb_component_id)
 
@@ -122,8 +123,8 @@ export async function convertCircuitJsonTo3D(
       center,
       size,
       color: componentColor,
-      meshUrl: model_stl_url || model_obj_url,
-      meshType: model_stl_url ? "stl" : "obj",
+      meshUrl: model_stl_url || model_obj_url || model_gltf_url,
+      meshType: model_stl_url ? "stl" : model_obj_url ? "obj" : "gltf",
     }
 
     // Add rotation if specified
@@ -139,6 +140,8 @@ export async function convertCircuitJsonTo3D(
         box.mesh = await loadSTL(model_stl_url, defaultTransform)
       } else if (model_obj_url) {
         box.mesh = await loadOBJ(model_obj_url, defaultTransform)
+      } else if (model_gltf_url) {
+        box.mesh = await loadGLTF(model_gltf_url, defaultTransform)
       }
     } catch (error) {
       console.warn(`Failed to load 3D model: ${error}`)

lib/gltf/geometry.ts

@@ -1,4 +1,4 @@
-import type { Point3, Size3, STLMesh, OBJMesh, Triangle } from "../types"
+import type { Point3, Size3, STLMesh, OBJMesh, GLTFMesh, Triangle } from "../types"
 
 export interface MeshData {
   positions: number[]
@@ -360,6 +360,31 @@ export function createMeshFromOBJ(
     : [{ meshData: createMeshFromSTL(objMesh), materialIndex: -1 }]
 }
 
+export function createMeshFromGLTF(gltfMesh: GLTFMesh): MeshData {
+  const positions: number[] = []
+  const normals: number[] = []
+  const texcoords: number[] = []
+  const indices: number[] = []
+
+  let vertexIndex = 0
+
+  for (const triangle of gltfMesh.triangles) {
+    // Add vertices
+    for (const vertex of triangle.vertices) {
+      positions.push(vertex.x, vertex.y, vertex.z)
+      normals.push(triangle.normal.x, triangle.normal.y, triangle.normal.z)
+      // Simple planar UV mapping
+      texcoords.push(vertex.x, vertex.z)
+    }
+
+    // Add indices (reverse winding for correct face orientation)
+    indices.push(vertexIndex, vertexIndex + 2, vertexIndex + 1)
+    vertexIndex += 3
+  }
+
+  return { positions, normals, texcoords, indices }
+}
+
 export function transformMesh(
   mesh: MeshData,
   translation: Point3,

lib/index.ts

@@ -44,6 +44,7 @@ export type {
   BoundingBox,
   STLMesh,
   OBJMesh,
+  GLTFMesh,
   OBJMaterial,
   Color,
   Box3D,
@@ -59,6 +60,7 @@ export type {
 // Re-export loaders
 export { loadSTL, clearSTLCache } from "./loaders/stl"
 export { loadOBJ, clearOBJCache } from "./loaders/obj"
+export { loadGLTF, clearGLTFCache } from "./loaders/gltf"
 
 // Re-export converters
 export { convertCircuitJsonTo3D } from "./converters/circuit-to-3d"