Augmented Reality
in WebRTC Browser
- Altanai Bisht
tara181989@gmail.com
http://altanaitelecom.wordpress.com

Who am I ?
★ Btech IT degree from Anna University , Chennai
★ 4 years in telecom industry
★ Frequent contributor to open source software
★ Write at : http://altanaitelecom.wordpress.com
★ Author of book “ WebRTC Integrator’s Guide “
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Altanai Bisht

Augmented reality (AR) is viewing a real-world
environment with elements that are
supplemented by computer-generated sensory
inputs such as sound, video, graphics , location
etc.
What is Augmented Reality ?
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How is it diff. from Virtual Reality ?
Virtual Reality Augmented Reality
replaces the real world with simulated
one
blending of virtual reality and real life
user is isolated from real life user interacts with real world through
digital overlays
Oculus Rift
Kinect
Google glass
Holo Lens
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Methods for rendering Augmented Reality
Computer Vision
Object Recognition
Eye Tracking
Face Detection and substitution
Emotion and gesture picker
Edge Detection
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Web :
WebRTC getusermedia
Web Speech API
WebGL
css
svg
HTML5 canvas
sensor API
Components of end -to-end web based
Augmented Reality solution
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H/w :
Graphics driver
microphone and camera
sensors
3D :
Geometry and Math Utilities
3D Model Loaders and models
Lights, Materials,Shaders, Particles,
Animation

WebRTC
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What is WebRTC ?
● Web based Real Time communications
● Definition for browser's media stream and data
● Awaiting more standardization , on a API level at the W3C and at the
protocol level at the IETF.
● Enable browser to browser applications for voice calling, video chat and
P2P file sharing without plugins.
● Enables web browsers with Real-Time Communications (RTC) capabilities
● MIT : Free, open project

WebRTC implements 3 APIs:
getUserMedia
RTCPeerConnection
RTCDataChannel
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API Stack

Code snippets for WebRTC
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1.To begin with WebRTC we first need to validate that the browser has permission to access the webcam.
<video id="webcam" autoplay width="640" height="480"></video>
2. Find out if the user's browser can use the getUserMedia API.
function hasGetUserMedia() { return !!(navigator.webkitGetUserMedia); }
3. Get the stream from the user's webcam.
var video = $('#webcam')[0];
if (navigator.webkitGetUserMedia) {
navigator.webkitGetUserMedia(
{audio:true, video:true},
function(stream) { video.src = window.webkitURL.createObjectURL(stream); },
function(e) { alert('Webcam error!', e); }
);
}

AppRTC
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Simple WebRTC API maintained by google
https://apprtc.appspot.com

TFX : collaboration and communication with webrtc
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TFX : collaboration and communication with webrtc
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What is WebGL?
● Web Graphics Library
● JavaScript API for rendering interactive 2D and 3D computer graphics in
browser
● no plugins
● uses GPU ( Graphics Processing Unit ) acceleration
● can mix with other HTML elements
● uses the HTML5 canvas element and is accessed using Document Object
Model interfaces
● cross platform , works on all major Desktop and mobile browsers

To get started you should know about :
● GLSL, the shading language used by OpenGL and WebGL
● Matrix computation to set up transformations
● Vertex buffers to hold data about vertex positions, normals, colors, and textures
● matrix math to animate shapes
Cleary WebGL is bit tough given the amount of careful coding , mapping and shading it requires .
Proceeding to some JS libraries that can make 3D easy for us .
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WebGL development

Building 3D graphics with
Javascript
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JS Libraries for 3D graphics
CCV
website : http://libccv.org/
SourceCode : https://github.com/liuliu/ccv
Demo:
Three.js
website : http://threejs.org/
SourceCode : https://github.com/mrdoob/three.js/
Demo: http://www.davidscottlyons.com/threejs/
Awe.js
Website : https://buildar.com/awe/tutorials/intro_to_awe.
js/index.html#
SourceCode : https://github.com/buildar/awe.js
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ArcuCO
SourceCode: https://github.com/jcmellado/js-aruco
Potree
website: http://potree.org/wp/
SourceCode: https://github.com/potree
Demo: http://potree.org/wp/demo/
Karenpeng
emotion & gesture-based arpeggiator and synthesizer
website:
SourceCode : https://github.com/karenpeng/motionEmotion
Demo: http://motionemotion.herokuapp.com/

Features
● MIT license
● javascript 3D engine ie ( WebGL
+ more)
● started a year ago
● under active development
● no dependencies or installation
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1. Set the scene , camera , renderer
2. Set the Mesh with Geometry & materials
3. Lights
4. Object properties
5. Add to scene , set camera position
6. Render with scene and camera
7. Animation
Steps
Three.js

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1. Spinning Colored Cube
2. Shaded Material on Sphere
3. Complicated materials like a bun
4. 3D on webcam input as texture
5. Motion Detection on webcam input
Lets Code !

1. Get three.js from : http://threejs.org/build/three.min.js
2. Make a empty HTML5 page and import the script + basic styling of page
<html>
<head>
<title>Spinning colored Cube</title>
<style>
body { margin: 0; }
canvas { width: 100%; height: 100% }
</style>
</head>
<body>
<script src="js/three.min.js"></script>
<script>// Our Javascript will go here. </script>
</body>
</html>
1. Spinning Colored Cube
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3. Scene
var scene = new THREE.Scene();
4. Camera
Camera types in three.js are CubeCamera , OrthographicCamera, PerspectiveCamera. We are using Perspective
camera here . Attributes are field of view , aspect ratio , near and far clipping plane.
var camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 0.1, 1000
);
5. Renderer
Renderer uses a <canvas> element to display the scene to us.
var renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
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6. BoxGeometry object contains all the points (vertices) and fill (faces) of the cube.
var geometry = new THREE.BoxGeometry( 1, 1, 1 );
7. Material
threejs has materials like - LineBasicMaterial , MeshBasicMaterial , MeshPhongMaterial , MeshLambertMaterial
These have their properties like -id, name, color , opacity , transparent etc. Use MeshBasicMaterial and color attribute of
0x00ff00, which is green.
var material = new THREE.MeshBasicMaterial( { color: 0x00ff00 } );
8. Mesh
A mesh is an object that takes a geometry, and applies a material to it, which we then can insert to our scene, and move freely
around.
var cube = new THREE.Mesh( geometry, material );
9. By default, when we call scene.add(), the thing we add will be added to the coordinates (0,0,0). This would cause both the
camera and the cube to be inside each other. To avoid this, we simply move the camera out a bit.
scene.add( cube );
camera.position.z = 5;
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10. Create a loop to render something on the screen
function render() {
requestAnimationFrame( render );
renderer.render( scene, camera );
}
render();
This will create a loop that causes the renderer to draw the scene 60 times per second.
11. Animating the cube
This will be run every frame (60 times per second), and give the cube a nice rotation animation
cube.rotation.x += 0.1;
cube.rotation.y += 0.1;
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output:
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2. Shaded Material on Sphere
1. create a empty page and import three.min.js and jquery
<html>
<head>
<title>Shaded Material on Sphere </title>
<style>
body { margin: 0; }
canvas { width: 100%; height: 100% }
</style>
<script src="js/jquery.min.js"></script>
<script src="js/three.min.js"></script>
<script>// Our Javascript will go here.</script>
</head>
<body>
<div id="container"></div>
</body>
</html>
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2. Repeat the same steps at in previous example
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(45, 600/600 , 0.1, 10000);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(600 , 600 );
$container.append(renderer.domElement);
scene.add(camera);
camera.position.z = 300; // the camera starts at 0,0,0 so pull it back
3. Create the sphere's material as MeshLambertMaterial
MeshLambertMaterial is non-shiny (Lambertian) surfaces, evaluated per vertex. Set the color to red .
var sphereMaterial = new THREE.MeshLambertMaterial( { color: 0xCC0000 });
4. create a new mesh with sphere geometry ( radius, segments, rings) and add to scene
var sphere = new THREE.Mesh( new THREE.SphereGeometry( 50, 16, 16 ), sphereMaterial);
scene.add(sphere);

5. Light
Create light , set its position and add it to scene as well . Light can be point light , spot light , directional light .
var pointLight = new THREE.PointLight(0xFFFFFF);
pointLight.position.x = 10;
pointLight.position.y = 50;
pointLight.position.z = 130;
scene.add(pointLight);
6. Render the whole thing
renderer.render(scene, camera);
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output:
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3. Complex objects like
Torusknot
1.Same as before make scene , camera and renderer
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(125, window.innerWidth / window.innerHeight, 1, 500);
camera.position.set(0, 0, 100);
camera.lookAt(new THREE.Vector3(0, 0, 0));
var renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
2. Add the lighting
var light = new THREE.PointLight(0xffffff);
light.position.set(0, 250, 0);
scene.add(light);
var ambientLight = new THREE.AmbientLight(0x111111);
scene.add(ambientLight);
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3. add Torusknotgeometry with radius, tube, radialSegments, tubularSegments, arc
var geometry = new THREE.TorusKnotGeometry( 8, 2, 100, 16, 4, 3 );
var material = new THREE.MeshLambertMaterial( { color: 0x2022ff } );
var torusKnot = new THREE.Mesh( geometry, material );
torusKnot.position.set(3, 3, 3);
scene.add( torusKnot );
camera.position.z =25;
4.do the animation and render on screen
var render = function () {
requestAnimationFrame( render );
torusKnot.rotation.x += 0.01;
torusKnot.rotation.y += 0.01;
renderer.render(scene, camera);
};
render();

output:
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4. 3D with webcam texture
Display the video as a plane which can be viewed from various angles in a given background landscape.
1.Use code from slide 10 to get user’s webcam input through getUserMedia
2. Make a Screen , camera and renderer as previously described
3. Give orbital CONTROLS for viewing the media plane from all angles
controls = new THREE.OrbitControls( camera, renderer.domElement );
4. Add point LIGHT to scene
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5. Make the FLOOR with an image texture
var floorTexture = new THREE.ImageUtils.loadTexture( 'imageURL.jpg' );
floorTexture.wrapS = floorTexture.wrapT = THREE.RepeatWrapping;
floorTexture.repeat.set( 10, 10 );
var floorMaterial = new THREE.MeshBasicMaterial({map: floorTexture, side: THREE.DoubleSide});
var floorGeometry = new THREE.PlaneGeometry(1000, 1000, 10, 10);
var floor = new THREE.Mesh(floorGeometry, floorMaterial);
floor.position.y = -0.5;
floor.rotation.x = Math.PI / 2;
scene.add(floor);
6. Add Fog
scene.fog = new THREE.FogExp2( 0x9999ff, 0.00025 );

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7.Add video Image Context and Texture.
video = document.getElementById( 'monitor' );
videoImage = document.getElementById( 'videoImage' );
videoImageContext = videoImage.getContext( '2d' );
videoImageContext.fillStyle = '#000000';
videoImageContext.fillRect( 0, 0, videoImage.width, videoImage.height );
videoTexture = new THREE.Texture( videoImage );
videoTexture.minFilter = THREE.LinearFilter;
videoTexture.magFilter = THREE.LinearFilter;
var movieMaterial=new THREE.MeshBasicMaterial({map:videoTexture,overdraw:true,side:THREE.DoubleSide});
var movieGeometry = new THREE.PlaneGeometry( 100, 100, 1, 1 );
var movieScreen = new THREE.Mesh( movieGeometry, movieMaterial );
movieScreen.position.set(0,50,0);
scene.add(movieScreen);

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8. Set camera position
camera.position.set(0,150,300);
camera.lookAt(movieScreen.position);
9. Define the render function
videoImageContext.drawImage( video, 0, 0, videoImage.width, videoImage.height );
renderer.render( scene, camera );
10. Animation
requestAnimationFrame( animate );
render();

output:
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4. Button touch detector
This example shows the process of triggering Web page activity by detecting motion using difference accuracy
1. Follow the same steps as in previous example
2. Define as many buttons
var buttons = [];
var button1 = new Image();
button1.src ="https://stemkoski.github.io/Three.js/images/SquareRed.png";
var buttonData1 = { name:"red", image:button1, x:320 - 96 - 30, y:10, w:32, h:32 };
buttons.push( buttonData1 );
3. make 3 layers of canvas for video , buttons and blended repectively .
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4. Define blend
// get current webcam image data
var sourceData = videoContext.getImageData(0, 0, width, height);
// create an image if the previous image doesn’t exist
if (!lastImageData) lastImageData = videoContext.getImageData(0, 0, width, height);
// create a ImageData instance to receive the blended result
var blendedData = videoContext.createImageData(width, height);
// blend the 2 images
differenceAccuracy(blendedData.data, sourceData.data, lastImageData.data);
// draw the result in a canvas
blendContext.putImageData(blendedData, 0, 0);
// store the current webcam image
lastImageData = sourceData;
5. Use mathematical logic for difference accuracy
6. The motion areas will be highlighted with white while no motion areas will become black.
7. check if white portion overlaps with buttons .

output Differential :
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output:

Other WebRTC WebGL 3D JS
applications
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karenLabs
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http://www.karenlabs.com/music/#.VUwvYFE4bK4

MotionEmotion
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http://motionemotion.herokuapp.com/

Mosh.io
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http://www.karenlabs.com/music/#.VUwvYFE4bK4

DeerHeaven
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http://hayleejung.com/deerheaven/
motion and gesture detector using webcam inout

Cubeslam
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https://www.cubeslam.com/mgeumt
WebRTC based 2 party game

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Thats all folks !