fix meshopt offset mistake

serve/src/index.js

@@ -1,46 +1,53 @@
 let app = new PIXI.Application({
-  backgroundColor: 0xdddddd, resizeTo: window, antialias: true
-})
-document.body.appendChild(app.view)
-globalThis.__PIXI_APP__ = app
+  backgroundColor: 0xdddddd,
+  resizeTo: window,
+  antialias: true,
+});
+document.body.appendChild(app.view);
+globalThis.__PIXI_APP__ = app;
 
-let control = new PIXI3D.CameraOrbitControl(app.view)
-control.enableDamping = true
+let control = new PIXI3D.CameraOrbitControl(app.view);
+control.enableDamping = true;
 
-app.loader.add("assets/chromatic/diffuse.cubemap")
-app.loader.add("assets/chromatic/specular.cubemap")
-app.loader.add("assets/teapot/teapot.gltf")
+app.loader.add("assets/chromatic/diffuse.cubemap");
+app.loader.add("assets/chromatic/specular.cubemap");
+app.loader.add("assets/teapot/teapot-meshopt.glb");
 
 app.loader.load((_, resources) => {
-  PIXI3D.LightingEnvironment.main.imageBasedLighting = new PIXI3D.ImageBasedLighting(
-    resources["assets/chromatic/diffuse.cubemap"].cubemap,
-    resources["assets/chromatic/specular.cubemap"].cubemap
-  )
+  PIXI3D.LightingEnvironment.main.imageBasedLighting =
+    new PIXI3D.ImageBasedLighting(
+      resources["assets/chromatic/diffuse.cubemap"].cubemap,
+      resources["assets/chromatic/specular.cubemap"].cubemap
+    );
 
   let model = app.stage.addChild(
-    PIXI3D.Model.from(resources["assets/teapot/teapot.gltf"].gltf))
-  model.y = -0.8
-  model.meshes.forEach(mesh => {
-    mesh.material.exposure = 1.3
-  })
+    PIXI3D.Model.from(resources["assets/teapot/teapot-meshopt.glb"].gltf)
+  );
+  model.y = -0.8;
+  model.meshes.forEach((mesh) => {
+    mesh.material.exposure = 1.3;
+  });
 
-  let ground = app.stage.addChild(PIXI3D.Mesh3D.createPlane())
-  ground.y = -0.8
-  ground.scale.set(10, 1, 10)
+  let ground = app.stage.addChild(PIXI3D.Mesh3D.createPlane());
+  ground.y = -0.8;
+  ground.scale.set(10, 1, 10);
 
   let directionalLight = Object.assign(new PIXI3D.Light(), {
     intensity: 1,
-    type: "directional"
-  })
-  directionalLight.rotationQuaternion.setEulerAngles(25, 120, 0)
-  PIXI3D.LightingEnvironment.main.lights.push(directionalLight)
+    type: "directional",
+  });
+  directionalLight.rotationQuaternion.setEulerAngles(25, 120, 0);
+  PIXI3D.LightingEnvironment.main.lights.push(directionalLight);
 
   let shadowCastingLight = new PIXI3D.ShadowCastingLight(
-    app.renderer, directionalLight, { shadowTextureSize: 1024, quality: PIXI3D.ShadowQuality.medium })
-  shadowCastingLight.softness = 1
-  shadowCastingLight.shadowArea = 15
-
-  let pipeline = app.renderer.plugins.pipeline
-  pipeline.enableShadows(ground, shadowCastingLight)
-  pipeline.enableShadows(model, shadowCastingLight)
-})
+    app.renderer,
+    directionalLight,
+    { shadowTextureSize: 1024, quality: PIXI3D.ShadowQuality.medium }
+  );
+  shadowCastingLight.softness = 1;
+  shadowCastingLight.shadowArea = 15;
+
+  let pipeline = app.renderer.plugins.pipeline;
+  pipeline.enableShadows(ground, shadowCastingLight);
+  pipeline.enableShadows(model, shadowCastingLight);
+});

src/gltf/gltf-parser.ts

@@ -79,9 +79,11 @@ export class glTFParser {
     }
     let bufferView = this._descriptor.bufferViews[accessor.bufferView || 0];
     let offset = accessor.byteOffset || 0;
+
     if (bufferView.byteOffset !== undefined) {
       offset += bufferView.byteOffset;
     }
+
     let size = accessor.count * componentCount[accessor.type];
     if (bufferView.byteStride !== undefined && bufferView.byteStride !== 0) {
       size =
@@ -96,7 +98,7 @@ export class glTFParser {
     if (bufferView.extensions?.EXT_meshopt_compression != undefined) {
       const meshoptExtension = bufferView.extensions.EXT_meshopt_compression;
       buffer = this.decodeMeshoptBuffer(meshoptExtension);
-      offset = 0;
+      offset = accessor.byteOffset || 0;
     }
 
     return glTFAttribute.from(