chore: update ar example

examples/demos/ar.ts

@@ -14,7 +14,7 @@ import {
  CompareFunction,
 } from '../../src';
 import { initExample } from './utils';
-import { vec3, mat4 } from 'gl-matrix';
+import { vec3, mat4, quat } from 'gl-matrix';
 import {
  cubeVertexArray,
  cubeVertexSize,
@@ -160,6 +160,14 @@ void main() {
  const referenceSpace = await session.requestReferenceSpace('local');
 
  const modelViewProjectionMatrix = mat4.create();
+ const modelViewMatrix = mat4.create();
+ const modelMatrix = mat4.fromRotationTranslationScale(
+ mat4.create(),
+ quat.create(),
+ vec3.fromValues(0, 0, 0),
+ vec3.fromValues(0.2, 0.2, 0.2),
+ );
+
  const onXRFrame: XRFrameRequestCallback = (time, frame) => {
  // Queue up the next draw request.
  session.requestAnimationFrame(onXRFrame);
@@ -182,7 +190,13 @@ void main() {
  // Use the view's transform matrix and projection matrix
  const viewMatrix = view.transform.matrix;
  const projectionMatrix = view.projectionMatrix;
- mat4.multiply(modelViewProjectionMatrix, projectionMatrix, viewMatrix);
+
+ mat4.multiply(modelViewMatrix, viewMatrix, modelMatrix);
+ mat4.multiply(
+ modelViewProjectionMatrix,
+ projectionMatrix,
+ modelViewMatrix,
+ );
 
  uniformBuffer.setSubData(
  0,