slides - JS(Saturday)
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WebGL - use JavaScript for 3D
visualization
By Christo Tsvetanov
Who am I?
An Infragistics friend
A long term enthusiast of 3D
Fascinates of mobile perspectives
Web Graphics Library
A Khronos group standard
JavaScript meets the GPU
Fast programmable drawing
OpenGL ES 2.0 for HTML5 Canvas
Desktop Browsers
Google Chrome – WebGL has been enabled
on all platforms that have a capable graphics
card
Mozilla Firefox
Safari – disabled by default
Opera
Internet Explorer - using third-party plugins
such as using third-party plugins such as
IEWebGL
Mobile Browsers
Nokia N900
BlackBerry PlayBook
Google Chrome for Android
Firefox for mobile for Android
The Sony Ericsson Xperia range of Android
Opera Mobile 12 final for Android
Tizen 1.0
3D Theory
3D Objects
Meshes, Vertices, Faces and Normals
Colors and Textures
Phong reflection model
UV Mapping
Transformations
Matrices
Shader-based drawing
Meshes
A polygon mesh
is a collection of
vertices, edges
and faces that
defines the shape
of a polyhedral
object in 3D
computer
graphics and
solid modeling
Vertex (vertices)
Face
Normal vector
Faces visibility
Phong reflection model
Ambient
Ambient color is the color of an object where it is in
shadow. This color is what the object reflects when
illuminated by ambient light rather than direct light.
Diffuse
Diffuse color is the most instinctive meaning of the
color of an object. It is that essential color that the
object reveals under pure white light. It is perceived
as the color of the object itself rather than a
reflection of the light.
Phong reflection model
Emissive
This is the self-illumination color an object has.
Specular
Specular color is the color of the light of a specular
reflection (specular reflection is the type of reflection
that is characteristic of light reflected from a shiny
surface)
Phong reflection model
UV mapping
World (Model – View) Matrix
World (Model – View) Matrix
worldMatrix = rotateMatrix * translateMatrix
* scaleMatrix
rotateMatrix = rotateX * rotateY *rotateZ
WebGL (glMatrix)
var mvMatrix = mat4.create();
mat4.translate(mvMatrix, [-1.5, 0.0, -7.0]);
mat4.rotate(mvMatrix, degToRad(rTri), [0, 1, 0]);
… rotateX, rotateY, rotateZ, scale
View (Camera) Matrix
Projection Matrix
Projection Matrix
WebGL
var pMatrix = mat4.create();
mat4.perspective(45, gl.viewportWidth /
gl.viewportHeight, 0.1, 100.0, pMatrix);
Shaders
Shaders are computer programs that runs on
the graphics processing unit and are used to
do shading - the production of appropriate
levels of light and darkness within an image.
Vertex shader
Run once for each vertex given to the graphics
processor
Pixel (fragment) shader
Compute color and other attributes of each pixel
Pipeline
Buffers
Uniform variables
Attributes
Varying variables
Modified varying
variables
Vertex shader
attribute vec3 aVertexPosition;
attribute vec4 aVertexColor;
uniform mat4 uMVMatrix;
uniform mat4 uPMatrix;
varying vec4 vColor;
void main(void) {
gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0);
vColor = aVertexColor;
}
Fragment shader
precision mediump float;
varying vec4 vColor;
void main(void) {
gl_FragColor = vColor;
}
WebGL demo
http://learningwebgl.com/lessons/lesson04/i
ndex.html
Three.js
Three.js is a lightweight crossbrowser JavaScript library/API used to create
and display animated 3D computer
graphics on a Web browser. Three.js scripts
may be used in conjunction with
the HTML5canvas element, SVG or WebGL.
Features
Renderers: Canvas, SVG and WebGL.
Effects: Anaglyph, cross-eyed and parallax
barrier.
Scenes: add and remove objects at run-time; fog
Cameras: perspective and orthographic;
controllers: trackball, FPS, path and more
Animation: armatures, forward
kinematics, inverse
kinematics, morph and keyframe
Features
Lights: ambient, direction, point and spot
lights; shadows: cast and receive
Materials: Lambert, Phong, smooth shading,
textures and more
Shaders: access to full OpenGL Shading
Language (GLSL) capabilities: lens flare, depth
pass and extensive post-processing library
Objects: meshes, particles, sprites, lines,
ribbons, bones and more - all with Level of
detail
Features
Geometry: plane, cube, sphere, torus, 3D text
and more; modifiers: lathe, extrude and tube
Data loaders: binary, image, JSON and scene
Utilities: full set of time and 3D math
functions including frustum,
matrix, Quaternian, UVs and more
Export and import: utilities to create Three.jscompatible JSON files from
within: Blender, openCTM, FBX, Max, and OBJ
Features
Support: API documentation is under
construction, public forum and wiki in full
operation
Examples: Over 150 files of coding examples
plus fonts, models, textures, sounds and
other support files
Debugging: Stats.js, WebGL
Inspector, Three.js Inspector
Variables and functions
var renderer;
var scene;
var camera;
var cubeMesh;
initializeScene();
animateScene();
Create a render
if (Detector.webgl) {
renderer = new THREE.WebGLRenderer({
antialias : true
});
} else {
renderer = new THREE.CanvasRenderer();
}
Set the renderer
renderer.setSize(canvasWidth, canvasHeight);
document.getElementById("WebGLCanvas").ap
pendChild(renderer.domElement);
Create the scene and camera
scene = new THREE.Scene();
camera = new THREE.PerspectiveCamera(45,
canvasWidth / canvasHeight, 1, 100);
camera.position.set(0, 0, 10);
camera.lookAt(scene.position);
scene.add(camera);
Create mesh – texture, geometry, material
var cubeGeometry = new
THREE.CubeGeometry(2.0, 2.0, 2.0);
var sponsorsTexture = new
THREE.ImageUtils.loadTexture("Sponsors.png");
var cubeMaterial = new
THREE.MeshBasicMaterial({
map : sponsorsTexture,
side : THREE.DoubleSide
});
Create mesh and add to scene
cubeMesh = new THREE.Mesh(cubeGeometry,
cubeMaterial);
cubeMesh.position.set(0.0, 0.0, 4.0);
scene.add(cubeMesh);
Animate
function animateScene() {
xRotation += xSpeed;
yRotation += ySpeed;
cubeMesh.rotation.set(xRotation, yRotation, zRotation);
cubeMesh.position.z = zTranslation;
requestAnimationFrame(animateScene);
renderer.render(scene, camera);
}
Links - WebGL
Tutorial:
http://learningwebgl.com/blog/?page_id=1217
Matrix library – glMatrix
https://code.google.com/p/glmatrix/
Links – three.js
Source
http://mrdoob.github.io/
Expect very soon: SharePoint Saturday!
Saturday, June 8, 2013
Same familiar format – 1 day filled with sessions
focused on SharePoint technologies
Best SharePoint professionals in the region
Registrations will be open next week (15th)!
www.SharePointSaturday.eu
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