Update index.html

public/index.html

@@ -52,6 +52,44 @@ renderer.autoClear = false;
 const camera = new THREE.PerspectiveCamera();
 camera.matrixAutoUpdate = false;
 
+// Initialize a WebXR session using "immersive-ar".
+const session = await navigator.xr.requestSession("immersive-ar");
+session.updateRenderState({
+  baseLayer: new XRWebGLLayer(session, gl)
+});
+
+// A 'local' reference space has a native origin that is located
+// near the viewer's position at the time the session was created.
+const referenceSpace = await session.requestReferenceSpace('local');
+// Create a render loop that allows us to draw on the AR view.
+const onXRFrame = (time, frame) => {
+  // Queue up the next draw request.
+  session.requestAnimationFrame(onXRFrame);
+
+  // Bind the graphics framebuffer to the baseLayer's framebuffer
+  gl.bindFramebuffer(gl.FRAMEBUFFER, session.renderState.baseLayer.framebuffer)
+
+  // Retrieve the pose of the device.
+  // XRFrame.getViewerPose can return null while the session attempts to establish tracking.
+  const pose = frame.getViewerPose(referenceSpace);
+  if (pose) {
+    // In mobile AR, we only have one view.
+    const view = pose.views[0];
+
+    const viewport = session.renderState.baseLayer.getViewport(view);
+    renderer.setSize(viewport.width, viewport.height)
+
+    // Use the view's transform matrix and projection matrix to configure the THREE.camera.
+    camera.matrix.fromArray(view.transform.matrix)
+    camera.projectionMatrix.fromArray(view.projectionMatrix);
+    camera.updateMatrixWorld(true);
+
+    // Render the scene with THREE.WebGLRenderer.
+    renderer.render(scene, camera)
+  }
+}
+session.requestAnimationFrame(onXRFrame);
+
 
   // To be continued in upcoming steps.
 }