index.html

<!doctype html>
<html>

<head>
  <meta charset="UTF-8">
  <meta name="viewport"
    content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <title>Cube Demo</title>

  <!-- three.js -->
  <script src="https://unpkg.com/three@0.126.0/build/three.js"></script>
</head>

<body>

  <!-- Starting an immersive WebXR session requires user interaction.
    We start this one with a simple button. -->
  <button onclick="activateXR()">Start Cube Demo</button>
  <script>
    async function activateXR() {
  // Add a canvas element and initialize a WebGL context that is compatible with WebXR.
  const canvas = document.createElement("canvas");
  document.body.appendChild(canvas);
  const gl = canvas.getContext("webgl", {xrCompatible: true});

  const scene = new THREE.Scene();


// Enable shadows in the renderer.
renderer.shadowMap.enabled = true;

// Create the cube and add it to the demo scene.
const cubeGeometry = new THREE.BoxBufferGeometry(0.5, 0.5, 0.5);
const cubeMaterials = [
  new THREE.MeshLambertMaterial({ color: 0xff0000 }), // Red
  new THREE.MeshLambertMaterial({ color: 0x0000ff }), // Blue
  new THREE.MeshLambertMaterial({ color: 0x00ff00 }), // Green
  new THREE.MeshLambertMaterial({ color: 0xff00ff }), // Magenta
  new THREE.MeshLambertMaterial({ color: 0x00ffff }), // Cyan
  new THREE.MeshLambertMaterial({ color: 0xffff00 })  // Yellow
 ];
 const cube = new THREE.Mesh(cubeGeometry, cubeMaterials);
 cube.position.set(0, 0, -1);
 cube.castShadow = true; // Enable shadow casting
 scene.add(cube);


// // Create a sphere geometry.
const sphereGeometry = new THREE.SphereBufferGeometry(0.3, 32, 32); // Adjust the radius and other parameters as needed.

// // Create a material for the sphere (you can customize the color).
const sphereMaterial = new THREE.MeshBasicMaterial({ color: 0xffff00 });

// // Create the sphere and add it to the scene.
const sphere = new THREE.Mesh(sphereGeometry, sphereMaterial);
sphere.position.set(1, 0, -1); // Position the sphere next to the cube.
scene.add(sphere);

const scene = new THREE.Scene();

const directionalLight = new THREE.DirectionalLight(0xffffff, 0.3);
directionalLight.position.set(10, 15, 10);
scene.add(directionalLight);

const session = await navigator.xr.requestSession("immersive-ar", {requiredFeatures: ['hit-test']});

<!-- three.js -->
<script src="https://unpkg.com/three@0.126.0/build/three.js">
  </script>

  <script src="https://unpkg.com/three@0.126.0/examples/js/loaders/GLTFLoader.js"></script>

  const loader = new THREE.GLTFLoader();
  let reticle;
  loader.load("https://immersive-web.github.io/webxr-samples/media/gltf/reticle/reticle.gltf", function(gltf) {
  reticle = gltf.scene;
  reticle.visible = false;
  scene.add(reticle);
  })

  let flower;
  loader.load("https://immersive-web.github.io/webxr-samples/media/gltf/sunflower/sunflower.gltf", function(gltf) {
  flower = gltf.scene;
  });

  // Create a render loop that allows us to draw on the AR view.
  const onXRFrame = (time, frame) => {

  // 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 another XRReferenceSpace that has the viewer as the origin.
  const viewerSpace = await session.requestReferenceSpace('viewer');
  // Perform hit testing using the viewer as origin.
  const hitTestSource = await session.requestHitTestSource({ space: viewerSpace });

  camera.projectionMatrix.fromArray(view.projectionMatrix);
  camera.updateMatrixWorld(true);

  const hitTestResults = frame.getHitTestResults(hitTestSource);
  if (hitTestResults.length > 0 && reticle) {
  const hitPose = hitTestResults[0].getPose(referenceSpace);
  reticle.visible = true;
  reticle.position.set(hitPose.transform.position.x, hitPose.transform.position.y, hitPose.transform.position.z)
  reticle.updateMatrixWorld(true);
  }

  let flower;
  loader.load("https://immersive-web.github.io/webxr-samples/media/gltf/sunflower/sunflower.gltf", function(gltf) {
  flower = gltf.scene;
  });

  session.addEventListener("select", (event) => {
  if (flower) {
  const clone = flower.clone();
  clone.position.copy(reticle.position);
  scene.add(clone);
  }
  });


  // 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);


  }
  </script>
</body>

</html