| <!doctype html> |
| <!-- |
| Copyright 2018 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>Immersive VR Session</title> |
| </head> |
| <body> |
| <header> |
| <details open> |
| <summary>Immersive VR Session</summary> |
| <p> |
| This sample demonstrates how to use an 'immersive-vr' XRSession to |
| present a simple WebGL scene to an XR device. The scene is not |
| rendered to the page. |
| <a class="back" href="./">Back</a> |
| </p> |
| </details> |
| </header> |
| <main style='text-align: center;'> |
| <p>Click 'Enter XR' to see content</p> |
| </main> |
| <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 {Gltf2Node} from './js/render/nodes/gltf2.js'; |
| import {SkyboxNode} from './js/render/nodes/skybox.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(); |
| } |
| |
| // XR globals. |
| let xrButton = null; |
| let xrRefSpace = null; |
| |
| // WebGL scene globals. |
| let gl = null; |
| let renderer = null; |
| let scene = new Scene(); |
| scene.addNode(new Gltf2Node({url: 'media/gltf/space/space.gltf'})); |
| scene.addNode(new SkyboxNode({url: 'media/textures/milky-way-4k.png'})); |
| |
| // Checks to see if WebXR is available and, if so, queries a list of |
| // XRDevices that are connected to the system. |
| function initXR() { |
| // Adds a helper button to the page that indicates if any XRDevices are |
| // available and let's the user pick between them if there's multiple. |
| xrButton = new WebXRButton({ |
| onRequestSession: onRequestSession, |
| onEndSession: onEndSession |
| }); |
| document.querySelector('header').appendChild(xrButton.domElement); |
| |
| // Is WebXR available on this UA? |
| if (navigator.xr) { |
| // If the device allows creation of exclusive sessions set it as the |
| // target of the 'Enter XR' button. |
| navigator.xr.isSessionSupported('immersive-vr').then((supported) => { |
| xrButton.enabled = supported; |
| }); |
| } |
| } |
| |
| // Called when the user selects a device to present to. In response we |
| // will request an exclusive session from that device. |
| function onRequestSession() { |
| return navigator.xr.requestSession('immersive-vr').then(onSessionStarted); |
| } |
| |
| // Called when we've successfully acquired a XRSession. In response we |
| // will set up the necessary session state and kick off the frame loop. |
| function onSessionStarted(session) { |
| // This informs the 'Enter XR' button that the session has started and |
| // that it should display 'Exit XR' instead. |
| xrButton.setSession(session); |
| |
| // Listen for the sessions 'end' event so we can respond if the user |
| // or UA ends the session for any reason. |
| session.addEventListener('end', onSessionEnded); |
| |
| // Create a WebGL context to render with, initialized to be compatible |
| // with the XRDisplay we're presenting to. |
| gl = createWebGLContext({ |
| xrCompatible: true |
| }); |
| |
| // Create a renderer with that GL context (this is just for the samples |
| // framework and has nothing to do with WebXR specifically.) |
| renderer = new Renderer(gl); |
| |
| // Set the scene's renderer, which creates the necessary GPU resources. |
| scene.setRenderer(renderer); |
| |
| // Use the new WebGL context to create a XRWebGLLayer and set it as the |
| // sessions baseLayer. This allows any content rendered to the layer to |
| // be displayed on the XRDevice. |
| session.updateRenderState({ baseLayer: new XRWebGLLayer(session, gl) }); |
| |
| // Get a frame of reference, which is required for querying poses. In |
| // this case an 'local' frame of reference means that all poses will |
| // be relative to the location where the XRDevice was first detected. |
| session.requestReferenceSpace('local').then((refSpace) => { |
| xrRefSpace = refSpace; |
| |
| // Inform the session that we're ready to begin drawing. |
| session.requestAnimationFrame(onXRFrame); |
| }); |
| } |
| |
| // Called when the user clicks the 'Exit XR' button. In response we end |
| // the session. |
| function onEndSession(session) { |
| session.end(); |
| } |
| |
| // Called either when the user has explicitly ended the session (like in |
| // onEndSession()) or when the UA has ended the session for any reason. |
| // At this point the session object is no longer usable and should be |
| // discarded. |
| function onSessionEnded(event) { |
| xrButton.setSession(null); |
| |
| // In this simple case discard the WebGL context too, since we're not |
| // rendering anything else to the screen with it. |
| renderer = null; |
| } |
| |
| // Called every time the XRSession requests that a new frame be drawn. |
| function onXRFrame(t, frame) { |
| let session = frame.session; |
| |
| // Per-frame scene setup. Nothing WebXR specific here. |
| scene.startFrame(); |
| |
| // Inform the session that we're ready for the next frame. |
| session.requestAnimationFrame(onXRFrame); |
| |
| // Get the XRDevice pose relative to the Frame of Reference we created |
| // earlier. |
| let pose = frame.getViewerPose(xrRefSpace); |
| |
| // Getting the pose may fail if, for example, tracking is lost. So we |
| // have to check to make sure that we got a valid pose before attempting |
| // to render with it. If not in this case we'll just leave the |
| // framebuffer cleared, so tracking loss means the scene will simply |
| // disappear. |
| if (pose) { |
| let glLayer = session.renderState.baseLayer; |
| |
| // If we do have a valid pose, bind the WebGL layer's framebuffer, |
| // which is where any content to be displayed on the XRDevice must be |
| // rendered. |
| gl.bindFramebuffer(gl.FRAMEBUFFER, glLayer.framebuffer); |
| |
| // Clear the framebuffer |
| gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); |
| |
| // Loop through each of the views reported by the frame and draw them |
| // into the corresponding viewport. |
| for (let view of pose.views) { |
| let viewport = glLayer.getViewport(view); |
| gl.viewport(viewport.x, viewport.y, |
| viewport.width, viewport.height); |
| |
| // Draw this view of the scene. What happens in this function really |
| // isn't all that important. What is important is that it renders |
| // into the XRWebGLLayer's framebuffer, using the viewport into that |
| // framebuffer reported by the current view, and using the |
| // projection matrix and view transform from the current view. |
| // We bound the framebuffer and viewport up above, and are passing |
| // in the appropriate matrices here to be used when rendering. |
| scene.draw(view.projectionMatrix, view.transform); |
| } |
| } else { |
| // There's several options for handling cases where no pose is given. |
| // The simplest, which these samples opt for, is to simply not draw |
| // anything. That way the device will continue to show the last frame |
| // drawn, possibly even with reprojection. Alternately you could |
| // re-draw the scene again with the last known good pose (which is now |
| // likely to be wrong), clear to black, or draw a head-locked message |
| // for the user indicating that they should try to get back to an area |
| // with better tracking. In all cases it's possible that the device |
| // may override what is drawn here to show the user it's own error |
| // message, so it should not be anything critical to the application's |
| // use. |
| } |
| |
| // Per-frame scene teardown. Nothing WebXR specific here. |
| scene.endFrame(); |
| } |
| |
| // Start the XR application. |
| initXR(); |
| </script> |
| </body> |
| </html> |