Augmented Reality in WebRTC Browser

- Altanai Bishttara181989@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 RiftKinect

Google glassHolo 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 Detection5

Web :

WebRTC getusermediaWeb Speech APIWebGLcss svgHTML5 canvassensor API

Components of end -to-end web based Augmented Reality solution

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H/w :

Graphics drivermicrophone and camerasensors

3D :

Geometry and Math Utilities3D 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:

getUserMediaRTCPeerConnectionRTCDataChannel

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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>26

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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 MeshLambertMaterialMeshLambertMaterial 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. LightCreate 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 Torusknot1.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 datavar sourceData = videoContext.getImageData(0, 0, width, height);// create an image if the previous image doesn’t existif (!lastImageData) lastImageData = videoContext.getImageData(0, 0, width, height);// create a ImageData instance to receive the blended resultvar blendedData = videoContext.createImageData(width, height);// blend the 2 imagesdifferenceAccuracy(blendedData.data, sourceData.data, lastImageData.data);// draw the result in a canvasblendContext.putImageData(blendedData, 0, 0);// store the current webcam imagelastImageData = 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 !