const scene = new THREE.Scene();
// The cube will have a different color on each side.
const materials = [
new THREE.MeshBasicMaterial({color: 0xff0000}),
new THREE.MeshBasicMaterial({color: 0x0000ff}),
new THREE.MeshBasicMaterial({color: 0x00ff00}),
new THREE.MeshBasicMaterial({color: 0xff00ff}),
new THREE.MeshBasicMaterial({color: 0x00ffff}),
new THREE.MeshBasicMaterial({color: 0xffff00})
];
// Create the cube and add it to the demo scene.
const cube = new THREE.Mesh(new THREE.BoxBufferGeometry(0.2, 0.2, 0.2), materials);
cube.position.set(1, 1, 1);
scene.add(cube);
// Set up the WebGLRenderer, which handles rendering to the session's base layer.
const renderer = new THREE.WebGLRenderer({
alpha: true,
preserveDrawingBuffer: true,
canvas: canvas,
context: gl
});
renderer.autoClear = false;
// The API directly updates the camera matrices.
// Disable matrix auto updates so three.js doesn't attempt
// to handle the matrices independently.
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);