teleportation.html - external/github.com/immersive-web/webxr-samples.git - Git at Google

 <!doctype html>
 <!--
 Copyright 2019 The Immersive Web Community Group

 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in
 the Software without restriction, including without limitation the rights to
 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 the Software, and to permit persons to whom the Software is furnished to do so,
 subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 -->
 <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>Teleportation</title>
   </head>
   <body>
     <header>
       <details open>
         <summary>Teleportation</summary>
         <p>
           This sample demonstrates teleporting the viewer by updating the
           XRSession reference space. Select a point on the floor with a
           controller to teleport to it. Select the leftmost box to rotate to the
           left by 30 degrees. Selecting the rightmost box rotates the viewer by
           30 degrees to the right. Select the middle box to reset the
           viewer orientation.
           <a class="back" href="./index.html">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 {SkyboxNode} from './js/render/nodes/skybox.js';
       import {BoxBuilder} from './js/render/geometry/box-builder.js';
       import {PbrMaterial} from './js/render/materials/pbr.js';
       import {mat4, vec3, quat} from './js/render/math/gl-matrix.js';
       import {QueryArgs} from './js/util/query-args.js';

       // If requested, use the polyfill to provide support for mobile devices
       // and devices which only support WebVR.
       import WebXRPolyfill from './js/third-party/webxr-polyfill/build/webxr-polyfill.module.js';
       if (QueryArgs.getBool('usePolyfill', true)) {
         let polyfill = new WebXRPolyfill();
       }

       // If requested, don't display the frame rate info.
       let hideStats = QueryArgs.getBool('hideStats', false);

       // XR globals. Several additional reference spaces are required because of
       // how the teleportation mechanic in onSelect works.
       let xrButton = null;
       let xrImmersiveRefSpaceBase = null;
       let xrImmersiveRefSpaceOffset = null;
       let xrInlineRefSpaceBase = null;
       let xrInlineRefSpaceOffset = null;
       let xrViewerSpaces = {};

       let trackingSpaceOriginInWorldSpace = vec3.create();
       let trackingSpaceHeadingDegrees = 0;  // around +Y axis, positive angles rotate left
       let floorSize = 10;
       let floorPosition = [0, -floorSize / 2 + 0.01, 0];
       let floorNode = null;

       // WebGL scene globals.
       let gl = null;
       let renderer = null;
       let scene = new Scene();
       if (hideStats) {
         scene.enableStats(false);
       }
       scene.addNode(new Gltf2Node({url: 'media/gltf/cube-room/cube-room.gltf'}));
       scene.standingStats(true);

       let boxes = [];

       function initXR() {
         xrButton = new WebXRButton({
           onRequestSession: onRequestSession,
           onEndSession: onEndSession
         });
         document.querySelector('header').appendChild(xrButton.domElement);

         if (navigator.xr) {
           navigator.xr.isSessionSupported('immersive-vr').then((supported) => {
             xrButton.enabled = supported;
           });

           navigator.xr.requestSession('inline').then(onSessionStarted);
         }
       }

       function addBox(x, y, z, r, g, b, box_list) {
         let boxBuilder = new BoxBuilder();
         boxBuilder.pushCube([0, 0, 0], 0.4);
         let boxPrimitive = boxBuilder.finishPrimitive(renderer);
         let boxMaterial = new PbrMaterial();
         boxMaterial.baseColorFactor.value = [r, g, b, 1.0];
         let boxRenderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);
         let boxNode = new Node();
         boxNode.addRenderPrimitive(boxRenderPrimitive);
         // Marks the node as one that needs to be checked when hit testing.
         boxNode.selectable = true;
         box_list.push({
           node: boxNode,
           renderPrimitive: boxRenderPrimitive,
           position: [x, y, z]
         });
         scene.addNode(boxNode);
       }

       function addFloorBox() {
         let boxBuilder = new BoxBuilder();
         boxBuilder.pushCube([0, 0, 0], floorSize);
         let boxPrimitive = boxBuilder.finishPrimitive(renderer);

         let boxMaterial = new PbrMaterial();
         boxMaterial.baseColorFactor.value = [0.3, 0.3, 0.3, 1.0];
         let boxRenderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);

         floorNode = new Node();
         floorNode.addRenderPrimitive(boxRenderPrimitive);
         floorNode.selectable = true;
         scene.addNode(floorNode);
         mat4.identity(floorNode.matrix);
         mat4.translate(floorNode.matrix, floorNode.matrix, floorPosition);
       }

       function initGL() {
         if (gl)
           return;

           gl = createWebGLContext({
           xrCompatible: true
         });
         document.body.appendChild(gl.canvas);

         function onResize() {
           gl.canvas.width = gl.canvas.clientWidth * window.devicePixelRatio;
           gl.canvas.height = gl.canvas.clientHeight * window.devicePixelRatio;
         }
         window.addEventListener('resize', onResize);
         onResize();

         renderer = new Renderer(gl);

         scene.setRenderer(renderer);

         // Create several boxes to use for hit testing.
         addBox(-1.0, 1.6, -1.3, 1.0, 0.0, 0.0, boxes);
         addBox(0.0, 1.7, -1.5, 0.0, 1.0, 0.0, boxes);
         addBox(1.0, 1.6, -1.3, 0.0, 0.0, 1.0, boxes);

         // Represent the floor as a box so that we can perform a hit test
         // against it onSelect so that we can teleport the user to that
         // particular location.
         addFloorBox();
       }

       function onRequestSession() {
         return navigator.xr.requestSession('immersive-vr', {
             requiredFeatures: ['local-floor']
         }).then((session) => {
           xrButton.setSession(session);
           session.isImmersive = true;
           onSessionStarted(session);
         });
       }

       function onSessionStarted(session) {
         session.addEventListener('end', onSessionEnded);

         // By listening for the 'select' event we can find out when the user has
         // performed some sort of primary input action and respond to it.
         session.addEventListener('select', onSelect);

         initGL();
         scene.inputRenderer.useProfileControllerMeshes(session);

         let glLayer = new XRWebGLLayer(session, gl);
         session.updateRenderState({ baseLayer: glLayer });

         session.requestReferenceSpace('local-floor').then((refSpace) => {
           console.log("created local-floor reference space");
           return refSpace;
         }, (e) => {
           if (!session.isImmersive) {
             // If we're in inline mode, our underlying platform may not support
             // the local-floor reference space, but a viewer space is guaranteed.
             console.log("falling back to viewer reference space");
             return session.requestReferenceSpace('viewer').then((viewerRefSpace) => {
               // Adjust the viewer space for an estimated user height. Otherwise,
               // the poses queried with this space will originate from the floor.
               let xform = new XRRigidTransform({x: 0, y: -1.5, z: 0});
               return viewerRefSpace.getOffsetReferenceSpace(xform);
             });
           } else {
             throw e;
           }
         }).then((refSpace) => {
           // Save the session-specific base reference space, and apply the current
           // player orientation/position as originOffset. This reference space
           // won't change for the duration of the session and is used when
           // updating the player position and/or orientation in onSelect.
           setRefSpace(session, refSpace, false);
           updateOriginOffset(session);

           session.requestReferenceSpace('viewer').then(function(viewerSpace){
             // Save a separate reference space that represents the tracking space
             // origin, which does not change for the duration of the session.
             // This is used when updating the player position and/or orientation
             // in onSelect.
             xrViewerSpaces[session.mode] = viewerSpace;
             session.requestAnimationFrame(onXRFrame);
           });
         });
       }

       // Used for updating the origin offset.
       let playerInWorldSpaceOld = vec3.create();
       let playerInWorldSpaceNew = vec3.create();
       let playerOffsetInWorldSpaceOld = vec3.create();
       let playerOffsetInWorldSpaceNew = vec3.create();
       let rotationDeltaQuat = quat.create();
       let invPosition = vec3.create();
       let invOrientation = quat.create();

       // If the user selected a point on the floor, teleport them to that
       // position while keeping their orientation the same.
       // Otherwise, check if one of the boxes was selected and update the
       // user's orientation accordingly:
       //    left box: turn left by 30 degrees
       //    center box: reset orientation
       //    right box: turn right by 30 degrees
       function onSelect(ev) {
         let session = ev.frame.session;
         let refSpace = getRefSpace(session, true);

         let headPose = ev.frame.getPose(xrViewerSpaces[session.mode], refSpace);
         if (!headPose) return;

         // Get the position offset in world space from the tracking space origin
         // to the player's feet. The headPose position is the head position in world space.
         // Subtract the tracking space origin position in world space to get a relative world space vector.
         vec3.set(playerInWorldSpaceOld, headPose.transform.position.x, 0, headPose.transform.position.z);
         vec3.sub(
           playerOffsetInWorldSpaceOld,
           playerInWorldSpaceOld,
           trackingSpaceOriginInWorldSpace);

         // based on https://github.com/immersive-web/webxr/blob/master/input-explainer.md#targeting-ray-pose
         let inputSourcePose = ev.frame.getPose(ev.inputSource.targetRaySpace, refSpace);
         if (!inputSourcePose) {
           return;
         }

         vec3.copy(playerInWorldSpaceNew, playerInWorldSpaceOld);
         let rotationDelta = 0;

         // Hit test results can change teleport position and orientation.
         let hitResult = scene.hitTest(inputSourcePose.transform);
         if (hitResult) {
           // Check to see if the hit result was one of our boxes.
           for (let i = 0; i < boxes.length; ++i) {
             let box = boxes[i];
             if (hitResult.node == box.node) {
               // Change the box color to something random.
               let uniforms = box.renderPrimitive.uniforms;
               uniforms.baseColorFactor.value = [Math.random(), Math.random(), Math.random(), 1.0];
               if (i == 0) {
                 // turn left
                 rotationDelta = 30;
               } else if (i == 1) {
                 // reset heading by undoing the current rotation
                 rotationDelta = -trackingSpaceHeadingDegrees;
               } else if (i == 2) {
                 // turn right
                 rotationDelta = -30;
               }
               console.log('rotate by', rotationDelta);
             }
           }
           if (hitResult.node == floorNode) {
              // New position uses x/z values of the hit test result, keeping y at 0 (floor level)
              playerInWorldSpaceNew[0] = hitResult.intersection[0];
              playerInWorldSpaceNew[1] = 0;
              playerInWorldSpaceNew[2] = hitResult.intersection[2];
              console.log('teleport to', playerInWorldSpaceNew);
           }
         }

         // Get the new world space offset vector from tracking space origin
         // to the player's feet, for the updated tracking space rotation.
         // Formally, this is the old world-space player offset transformed
         // into tracking space using the old originOffset's rotation component,
         // then transformed back into world space using the inverse of the
         // new originOffset. This simplifies to a rotation of the old player
         // offset by (new angle - old angle):
         //   worldOffsetNew = inv(rot_of(originOffsetNew)) * rot_of(originOffsetOld) * worldOffsetOld
         //       = inv(rotY(-angleNew)) * rotY(-angleOld) * worldOffsetOld
         //       = rotY(angleNew) * rotY(-angleOld) * worldOffsetOld
         //       = rotY(angleNew - angleOld) * worldOffsetOld
         quat.identity(rotationDeltaQuat);
         quat.rotateY(rotationDeltaQuat, rotationDeltaQuat, rotationDelta * Math.PI / 180);
         vec3.transformQuat(playerOffsetInWorldSpaceNew, playerOffsetInWorldSpaceOld, rotationDeltaQuat);
         trackingSpaceHeadingDegrees += rotationDelta;

         // Update tracking space origin so that origin + playerOffset == player location in world space
         vec3.sub(
           trackingSpaceOriginInWorldSpace,
           playerInWorldSpaceNew,
           playerOffsetInWorldSpaceNew);

         updateOriginOffset(session);
       }

       function updateOriginOffset(session) {
         // Compute the origin offset based on player position/orientation.
         quat.identity(invOrientation);
         quat.rotateY(invOrientation, invOrientation, -trackingSpaceHeadingDegrees * Math.PI / 180);
         vec3.negate(invPosition, trackingSpaceOriginInWorldSpace);
         vec3.transformQuat(invPosition, invPosition, invOrientation);
         let xform = new XRRigidTransform(
           {x: invPosition[0], y: invPosition[1], z: invPosition[2]},
           {x: invOrientation[0], y: invOrientation[1], z: invOrientation[2], w: invOrientation[3]});

         // Update offset reference to use a new originOffset with the teleported
         // player position and orientation.
         // This new offset needs to be applied to the base ref space.
         let refSpace = getRefSpace(session, false).getOffsetReferenceSpace(xform);
         setRefSpace(session, refSpace, true);

         console.log('teleport to', trackingSpaceOriginInWorldSpace);
       }

       function onEndSession(session) {
         session.end();
       }

       function onSessionEnded(event) {
         if (event.session.isImmersive) {
           xrButton.setSession(null);
         }
       }

       function getRefSpace(session, isOffset) {
         return session.isImmersive ?
               (isOffset ? xrImmersiveRefSpaceOffset : xrImmersiveRefSpaceBase) :
               (isOffset ? xrInlineRefSpaceOffset : xrInlineRefSpaceBase);
       }

       function setRefSpace(session, refSpace, isOffset) {
         if (session.isImmersive) {
           if (isOffset) {
             xrImmersiveRefSpaceOffset = refSpace;
           } else {
             xrImmersiveRefSpaceBase = refSpace;
           }
         } else {
           if (isOffset) {
             xrInlineRefSpaceOffset = refSpace;
           } else {
             xrInlineRefSpaceBase = refSpace;
           }
         }
       }

       function onXRFrame(time, frame) {
         let session = frame.session;
         let refSpace = getRefSpace(session, true);

         let pose = frame.getViewerPose(refSpace);
         scene.startFrame();
         session.requestAnimationFrame(onXRFrame);

         // Update the matrix for each box
         for (let box of boxes) {
           let node = box.node;
           mat4.identity(node.matrix);
           mat4.translate(node.matrix, node.matrix, box.position);
           mat4.rotateX(node.matrix, node.matrix, time/1000);
           mat4.rotateY(node.matrix, node.matrix, time/1500);
         }

         scene.updateInputSources(frame, refSpace);
         scene.drawXRFrame(frame, pose);
         scene.endFrame();
       }

       // Start the XR application.
       initXR();
     </script>
   </body>
 </html>
	<!doctype html>
	<!--
	Copyright 2019 The Immersive Web Community Group

	Permission is hereby granted, free of charge, to any person obtaining a copy of
	this software and associated documentation files (the "Software"), to deal in
	the Software without restriction, including without limitation the rights to
	use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
	the Software, and to permit persons to whom the Software is furnished to do so,
	subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
	FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
	COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	-->
	<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>Teleportation</title>
	</head>
	<body>
	<header>
	<details open>
	<summary>Teleportation</summary>
	<p>
	This sample demonstrates teleporting the viewer by updating the
	XRSession reference space. Select a point on the floor with a
	controller to teleport to it. Select the leftmost box to rotate to the
	left by 30 degrees. Selecting the rightmost box rotates the viewer by
	30 degrees to the right. Select the middle box to reset the
	viewer orientation.
	<a class="back" href="./index.html">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 {SkyboxNode} from './js/render/nodes/skybox.js';
	import {BoxBuilder} from './js/render/geometry/box-builder.js';
	import {PbrMaterial} from './js/render/materials/pbr.js';
	import {mat4, vec3, quat} from './js/render/math/gl-matrix.js';
	import {QueryArgs} from './js/util/query-args.js';

	// If requested, use the polyfill to provide support for mobile devices
	// and devices which only support WebVR.
	import WebXRPolyfill from './js/third-party/webxr-polyfill/build/webxr-polyfill.module.js';
	if (QueryArgs.getBool('usePolyfill', true)) {
	let polyfill = new WebXRPolyfill();
	}

	// If requested, don't display the frame rate info.
	let hideStats = QueryArgs.getBool('hideStats', false);

	// XR globals. Several additional reference spaces are required because of
	// how the teleportation mechanic in onSelect works.
	let xrButton = null;
	let xrImmersiveRefSpaceBase = null;
	let xrImmersiveRefSpaceOffset = null;
	let xrInlineRefSpaceBase = null;
	let xrInlineRefSpaceOffset = null;
	let xrViewerSpaces = {};

	let trackingSpaceOriginInWorldSpace = vec3.create();
	let trackingSpaceHeadingDegrees = 0; // around +Y axis, positive angles rotate left
	let floorSize = 10;
	let floorPosition = [0, -floorSize / 2 + 0.01, 0];
	let floorNode = null;

	// WebGL scene globals.
	let gl = null;
	let renderer = null;
	let scene = new Scene();
	if (hideStats) {
	scene.enableStats(false);
	}
	scene.addNode(new Gltf2Node({url: 'media/gltf/cube-room/cube-room.gltf'}));
	scene.standingStats(true);

	let boxes = [];

	function initXR() {
	xrButton = new WebXRButton({
	onRequestSession: onRequestSession,
	onEndSession: onEndSession
	});
	document.querySelector('header').appendChild(xrButton.domElement);

	if (navigator.xr) {
	navigator.xr.isSessionSupported('immersive-vr').then((supported) => {
	xrButton.enabled = supported;
	});

	navigator.xr.requestSession('inline').then(onSessionStarted);
	}
	}

	function addBox(x, y, z, r, g, b, box_list) {
	let boxBuilder = new BoxBuilder();
	boxBuilder.pushCube([0, 0, 0], 0.4);
	let boxPrimitive = boxBuilder.finishPrimitive(renderer);
	let boxMaterial = new PbrMaterial();
	boxMaterial.baseColorFactor.value = [r, g, b, 1.0];
	let boxRenderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);
	let boxNode = new Node();
	boxNode.addRenderPrimitive(boxRenderPrimitive);
	// Marks the node as one that needs to be checked when hit testing.
	boxNode.selectable = true;
	box_list.push({
	node: boxNode,
	renderPrimitive: boxRenderPrimitive,
	position: [x, y, z]
	});
	scene.addNode(boxNode);
	}

	function addFloorBox() {
	let boxBuilder = new BoxBuilder();
	boxBuilder.pushCube([0, 0, 0], floorSize);
	let boxPrimitive = boxBuilder.finishPrimitive(renderer);

	let boxMaterial = new PbrMaterial();
	boxMaterial.baseColorFactor.value = [0.3, 0.3, 0.3, 1.0];
	let boxRenderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);

	floorNode = new Node();
	floorNode.addRenderPrimitive(boxRenderPrimitive);
	floorNode.selectable = true;
	scene.addNode(floorNode);
	mat4.identity(floorNode.matrix);
	mat4.translate(floorNode.matrix, floorNode.matrix, floorPosition);
	}

	function initGL() {
	if (gl)
	return;

	gl = createWebGLContext({
	xrCompatible: true
	});
	document.body.appendChild(gl.canvas);

	function onResize() {
	gl.canvas.width = gl.canvas.clientWidth * window.devicePixelRatio;
	gl.canvas.height = gl.canvas.clientHeight * window.devicePixelRatio;
	}
	window.addEventListener('resize', onResize);
	onResize();

	renderer = new Renderer(gl);

	scene.setRenderer(renderer);

	// Create several boxes to use for hit testing.
	addBox(-1.0, 1.6, -1.3, 1.0, 0.0, 0.0, boxes);
	addBox(0.0, 1.7, -1.5, 0.0, 1.0, 0.0, boxes);
	addBox(1.0, 1.6, -1.3, 0.0, 0.0, 1.0, boxes);

	// Represent the floor as a box so that we can perform a hit test
	// against it onSelect so that we can teleport the user to that
	// particular location.
	addFloorBox();
	}

	function onRequestSession() {
	return navigator.xr.requestSession('immersive-vr', {
	requiredFeatures: ['local-floor']
	}).then((session) => {
	xrButton.setSession(session);
	session.isImmersive = true;
	onSessionStarted(session);
	});
	}

	function onSessionStarted(session) {
	session.addEventListener('end', onSessionEnded);

	// By listening for the 'select' event we can find out when the user has
	// performed some sort of primary input action and respond to it.
	session.addEventListener('select', onSelect);

	initGL();
	scene.inputRenderer.useProfileControllerMeshes(session);

	let glLayer = new XRWebGLLayer(session, gl);
	session.updateRenderState({ baseLayer: glLayer });

	session.requestReferenceSpace('local-floor').then((refSpace) => {
	console.log("created local-floor reference space");
	return refSpace;
	}, (e) => {
	if (!session.isImmersive) {
	// If we're in inline mode, our underlying platform may not support
	// the local-floor reference space, but a viewer space is guaranteed.
	console.log("falling back to viewer reference space");
	return session.requestReferenceSpace('viewer').then((viewerRefSpace) => {
	// Adjust the viewer space for an estimated user height. Otherwise,
	// the poses queried with this space will originate from the floor.
	let xform = new XRRigidTransform({x: 0, y: -1.5, z: 0});
	return viewerRefSpace.getOffsetReferenceSpace(xform);
	});
	} else {
	throw e;
	}
	}).then((refSpace) => {
	// Save the session-specific base reference space, and apply the current
	// player orientation/position as originOffset. This reference space
	// won't change for the duration of the session and is used when
	// updating the player position and/or orientation in onSelect.
	setRefSpace(session, refSpace, false);
	updateOriginOffset(session);

	session.requestReferenceSpace('viewer').then(function(viewerSpace){
	// Save a separate reference space that represents the tracking space
	// origin, which does not change for the duration of the session.
	// This is used when updating the player position and/or orientation
	// in onSelect.
	xrViewerSpaces[session.mode] = viewerSpace;
	session.requestAnimationFrame(onXRFrame);
	});
	});
	}

	// Used for updating the origin offset.
	let playerInWorldSpaceOld = vec3.create();
	let playerInWorldSpaceNew = vec3.create();
	let playerOffsetInWorldSpaceOld = vec3.create();
	let playerOffsetInWorldSpaceNew = vec3.create();
	let rotationDeltaQuat = quat.create();
	let invPosition = vec3.create();
	let invOrientation = quat.create();

	// If the user selected a point on the floor, teleport them to that
	// position while keeping their orientation the same.
	// Otherwise, check if one of the boxes was selected and update the
	// user's orientation accordingly:
	// left box: turn left by 30 degrees
	// center box: reset orientation
	// right box: turn right by 30 degrees
	function onSelect(ev) {
	let session = ev.frame.session;
	let refSpace = getRefSpace(session, true);

	let headPose = ev.frame.getPose(xrViewerSpaces[session.mode], refSpace);
	if (!headPose) return;

	// Get the position offset in world space from the tracking space origin
	// to the player's feet. The headPose position is the head position in world space.
	// Subtract the tracking space origin position in world space to get a relative world space vector.
	vec3.set(playerInWorldSpaceOld, headPose.transform.position.x, 0, headPose.transform.position.z);
	vec3.sub(
	playerOffsetInWorldSpaceOld,
	playerInWorldSpaceOld,
	trackingSpaceOriginInWorldSpace);

	// based on https://github.com/immersive-web/webxr/blob/master/input-explainer.md#targeting-ray-pose
	let inputSourcePose = ev.frame.getPose(ev.inputSource.targetRaySpace, refSpace);
	if (!inputSourcePose) {
	return;
	}

	vec3.copy(playerInWorldSpaceNew, playerInWorldSpaceOld);
	let rotationDelta = 0;

	// Hit test results can change teleport position and orientation.
	let hitResult = scene.hitTest(inputSourcePose.transform);
	if (hitResult) {
	// Check to see if the hit result was one of our boxes.
	for (let i = 0; i < boxes.length; ++i) {
	let box = boxes[i];
	if (hitResult.node == box.node) {
	// Change the box color to something random.
	let uniforms = box.renderPrimitive.uniforms;
	uniforms.baseColorFactor.value = [Math.random(), Math.random(), Math.random(), 1.0];
	if (i == 0) {
	// turn left
	rotationDelta = 30;
	} else if (i == 1) {
	// reset heading by undoing the current rotation
	rotationDelta = -trackingSpaceHeadingDegrees;
	} else if (i == 2) {
	// turn right
	rotationDelta = -30;
	}
	console.log('rotate by', rotationDelta);
	}
	}
	if (hitResult.node == floorNode) {
	// New position uses x/z values of the hit test result, keeping y at 0 (floor level)
	playerInWorldSpaceNew[0] = hitResult.intersection[0];
	playerInWorldSpaceNew[1] = 0;
	playerInWorldSpaceNew[2] = hitResult.intersection[2];
	console.log('teleport to', playerInWorldSpaceNew);
	}
	}

	// Get the new world space offset vector from tracking space origin
	// to the player's feet, for the updated tracking space rotation.
	// Formally, this is the old world-space player offset transformed
	// into tracking space using the old originOffset's rotation component,
	// then transformed back into world space using the inverse of the
	// new originOffset. This simplifies to a rotation of the old player
	// offset by (new angle - old angle):
	// worldOffsetNew = inv(rot_of(originOffsetNew)) * rot_of(originOffsetOld) * worldOffsetOld
	// = inv(rotY(-angleNew)) * rotY(-angleOld) * worldOffsetOld
	// = rotY(angleNew) * rotY(-angleOld) * worldOffsetOld
	// = rotY(angleNew - angleOld) * worldOffsetOld
	quat.identity(rotationDeltaQuat);
	quat.rotateY(rotationDeltaQuat, rotationDeltaQuat, rotationDelta * Math.PI / 180);
	vec3.transformQuat(playerOffsetInWorldSpaceNew, playerOffsetInWorldSpaceOld, rotationDeltaQuat);
	trackingSpaceHeadingDegrees += rotationDelta;

	// Update tracking space origin so that origin + playerOffset == player location in world space
	vec3.sub(
	trackingSpaceOriginInWorldSpace,
	playerInWorldSpaceNew,
	playerOffsetInWorldSpaceNew);

	updateOriginOffset(session);
	}

	function updateOriginOffset(session) {
	// Compute the origin offset based on player position/orientation.
	quat.identity(invOrientation);
	quat.rotateY(invOrientation, invOrientation, -trackingSpaceHeadingDegrees * Math.PI / 180);
	vec3.negate(invPosition, trackingSpaceOriginInWorldSpace);
	vec3.transformQuat(invPosition, invPosition, invOrientation);
	let xform = new XRRigidTransform(
	{x: invPosition[0], y: invPosition[1], z: invPosition[2]},
	{x: invOrientation[0], y: invOrientation[1], z: invOrientation[2], w: invOrientation[3]});

	// Update offset reference to use a new originOffset with the teleported
	// player position and orientation.
	// This new offset needs to be applied to the base ref space.
	let refSpace = getRefSpace(session, false).getOffsetReferenceSpace(xform);
	setRefSpace(session, refSpace, true);

	console.log('teleport to', trackingSpaceOriginInWorldSpace);
	}

	function onEndSession(session) {
	session.end();
	}

	function onSessionEnded(event) {
	if (event.session.isImmersive) {
	xrButton.setSession(null);
	}
	}

	function getRefSpace(session, isOffset) {
	return session.isImmersive ?
	(isOffset ? xrImmersiveRefSpaceOffset : xrImmersiveRefSpaceBase) :
	(isOffset ? xrInlineRefSpaceOffset : xrInlineRefSpaceBase);
	}

	function setRefSpace(session, refSpace, isOffset) {
	if (session.isImmersive) {
	if (isOffset) {
	xrImmersiveRefSpaceOffset = refSpace;
	} else {
	xrImmersiveRefSpaceBase = refSpace;
	}
	} else {
	if (isOffset) {
	xrInlineRefSpaceOffset = refSpace;
	} else {
	xrInlineRefSpaceBase = refSpace;
	}
	}
	}

	function onXRFrame(time, frame) {
	let session = frame.session;
	let refSpace = getRefSpace(session, true);

	let pose = frame.getViewerPose(refSpace);
	scene.startFrame();
	session.requestAnimationFrame(onXRFrame);

	// Update the matrix for each box
	for (let box of boxes) {
	let node = box.node;
	mat4.identity(node.matrix);
	mat4.translate(node.matrix, node.matrix, box.position);
	mat4.rotateX(node.matrix, node.matrix, time/1000);
	mat4.rotateY(node.matrix, node.matrix, time/1500);
	}

	scene.updateInputSources(frame, refSpace);
	scene.drawXRFrame(frame, pose);
	scene.endFrame();
	}

	// Start the XR application.
	initXR();
	</script>
	</body>
	</html>