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| <html> |
| <head> |
| <meta charset='utf-8'> |
| <meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no'> |
| <meta name='mobile-web-app-capable' content='yes'> |
| <meta name='apple-mobile-web-app-capable' content='yes'> |
| <link rel='icon' type='image/png' sizes='32x32' href='favicon-32x32.png'> |
| <link rel='icon' type='image/png' sizes='96x96' href='favicon-96x96.png'> |
| <link rel='stylesheet' href='css/common.css'> |
| |
| <title>Hit Test</title> |
| </head> |
| <body> |
| <header> |
| <details open> |
| <summary>Hit Test</summary> |
| <p> |
| This sample demonstrates the use of hit testing to place virtual objects on real-world surfaces. |
| <a class="back" href="./">Back</a> |
| </p> |
| </details> |
| </header> |
| <script type="module"> |
| import {WebXRButton} from './js/util/webxr-button.js'; |
| import {Scene} from './js/render/scenes/scene.js'; |
| import {Renderer, createWebGLContext} from './js/render/core/renderer.js'; |
| import {Node} from './js/render/core/node.js'; |
| import {Gltf2Node} from './js/render/nodes/gltf2.js'; |
| import {DropShadowNode} from './js/render/nodes/drop-shadow.js'; |
| import {vec3} from './js/render/math/gl-matrix.js'; |
| import {Ray} from './js/render/math/ray.js'; |
| |
| // XR globals. |
| let xrButton = null; |
| let xrRefSpace = null; |
| let xrViewerSpace = null; |
| let xrHitTestSource = null; |
| |
| // WebGL scene globals. |
| let gl = null; |
| let renderer = null; |
| let scene = new Scene(); |
| scene.enableStats(false); |
| |
| let arObject = new Node(); |
| arObject.visible = false; |
| scene.addNode(arObject); |
| |
| let flower = new Gltf2Node({url: 'media/gltf/sunflower/sunflower.gltf'}); |
| arObject.addNode(flower); |
| |
| let reticle = new Gltf2Node({url: 'media/gltf/reticle/reticle.gltf'}); |
| reticle.visible = false; |
| scene.addNode(reticle); |
| |
| // Having a really simple drop shadow underneath an object helps ground |
| // it in the world without adding much complexity. |
| let shadow = new DropShadowNode(); |
| vec3.set(shadow.scale, 0.15, 0.15, 0.15); |
| arObject.addNode(shadow); |
| |
| const MAX_FLOWERS = 30; |
| let flowers = []; |
| |
| // Ensure the background is transparent for AR. |
| scene.clear = false; |
| |
| function initXR() { |
| xrButton = new WebXRButton({ |
| onRequestSession: onRequestSession, |
| onEndSession: onEndSession, |
| textEnterXRTitle: "START AR", |
| textXRNotFoundTitle: "AR NOT FOUND", |
| textExitXRTitle: "EXIT AR", |
| }); |
| document.querySelector('header').appendChild(xrButton.domElement); |
| |
| if (navigator.xr) { |
| navigator.xr.isSessionSupported('immersive-ar') |
| .then((supported) => { |
| xrButton.enabled = supported; |
| }); |
| } |
| } |
| |
| function onRequestSession() { |
| return navigator.xr.requestSession('immersive-ar', {requiredFeatures: ['local', 'hit-test']}) |
| .then((session) => { |
| xrButton.setSession(session); |
| onSessionStarted(session); |
| }); |
| } |
| |
| function onSessionStarted(session) { |
| session.addEventListener('end', onSessionEnded); |
| session.addEventListener('select', onSelect); |
| |
| if (!gl) { |
| gl = createWebGLContext({ |
| xrCompatible: true |
| }); |
| |
| renderer = new Renderer(gl); |
| |
| scene.setRenderer(renderer); |
| } |
| |
| session.updateRenderState({ baseLayer: new XRWebGLLayer(session, gl) }); |
| |
| // In this sample we want to cast a ray straight out from the viewer's |
| // position and render a reticle where it intersects with a real world |
| // surface. To do this we first get the viewer space, then create a |
| // hitTestSource that tracks it. |
| session.requestReferenceSpace('viewer').then((refSpace) => { |
| xrViewerSpace = refSpace; |
| session.requestHitTestSource({ space: xrViewerSpace }).then((hitTestSource) => { |
| xrHitTestSource = hitTestSource; |
| }); |
| }); |
| |
| session.requestReferenceSpace('local').then((refSpace) => { |
| xrRefSpace = refSpace; |
| |
| session.requestAnimationFrame(onXRFrame); |
| }); |
| } |
| |
| function onEndSession(session) { |
| xrHitTestSource.cancel(); |
| xrHitTestSource = null; |
| session.end(); |
| } |
| |
| function onSessionEnded(event) { |
| xrButton.setSession(null); |
| } |
| |
| // Adds a new object to the scene at the |
| // specified transform. |
| function addARObjectAt(matrix) { |
| let newFlower = arObject.clone(); |
| newFlower.visible = true; |
| newFlower.matrix = matrix; |
| scene.addNode(newFlower); |
| |
| flowers.push(newFlower); |
| |
| // For performance reasons if we add too many objects start |
| // removing the oldest ones to keep the scene complexity |
| // from growing too much. |
| if (flowers.length > MAX_FLOWERS) { |
| let oldFlower = flowers.shift(); |
| scene.removeNode(oldFlower); |
| } |
| } |
| |
| let rayOrigin = vec3.create(); |
| let rayDirection = vec3.create(); |
| function onSelect(event) { |
| if (reticle.visible) { |
| // The reticle should already be positioned at the latest hit point, |
| // so we can just use it's matrix to save an unnecessary call to |
| // event.frame.getHitTestResults. |
| addARObjectAt(reticle.matrix); |
| } |
| } |
| |
| // Called every time a XRSession requests that a new frame be drawn. |
| function onXRFrame(t, frame) { |
| let session = frame.session; |
| let pose = frame.getViewerPose(xrRefSpace); |
| |
| reticle.visible = false; |
| |
| // If we have a hit test source, get its results for the frame |
| // and use the pose to display a reticle in the scene. |
| if (xrHitTestSource && pose) { |
| let hitTestResults = frame.getHitTestResults(xrHitTestSource); |
| if (hitTestResults.length > 0) { |
| let pose = hitTestResults[0].getPose(xrRefSpace); |
| reticle.visible = true; |
| reticle.matrix = pose.transform.matrix; |
| } |
| } |
| |
| scene.startFrame(); |
| |
| session.requestAnimationFrame(onXRFrame); |
| |
| scene.drawXRFrame(frame, pose); |
| |
| scene.endFrame(); |
| } |
| |
| // Start the XR application. |
| initXR(); |
| </script> |
| </body> |
| </html> |