Intro to WebGLwith Three.js

WebGL

JavaScript API for rendering interactive 2D and 3D graphics
inside an HTML <canvas> element.

Browser Support

three.js

threejs.org

3D Javascript Library

Renderers: WebGL, <canvas>, <svg>, CSS3D / DOM, and more

Scenes, Cameras, Geometry, 3D Model Loaders, Lights, Materials,
Shaders, Particles, Animation, Math Utilities

<!DOCTYPE html>
<html>
  <head>
    <title>Basic Three.js App</title>
    <style>
      html, body { margin: 0; padding: 0; overflow: hidden; }
    </style>
  </head>
  <body>
    <script src="js/three.min.js"></script>
    <script>
      // Javascript will go here.
    </script>
  </body>
</html>
var scene = new THREE.Scene();
var aspect = window.innerWidth / window.innerHeight;
var camera = new THREE.PerspectiveCamera( 75, aspect, 0.1, 1000 );
var renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );

var geometry = new THREE.BoxGeometry( 1, 1, 1 );
var material = new THREE.MeshNormalMaterial();
var cube = new THREE.Mesh( geometry, material );
scene.add( cube );
camera.position.z = 5;


var render = function () {
  requestAnimationFrame( render );
  cube.rotation.x += 0.1;
  cube.rotation.y += 0.1;
  renderer.render( scene, camera );
};
render();

Scene Graph

Object3D

var group = new THREE.Group();
scene.add( group );
group.add( mesh1 );
group.add( mesh2 );
mesh2.visible = false;
group.remove( mesh2 );
group.children // mesh1
group.parent // scene

Object3D Transforms

mesh.position.x = 0
mesh.position.x = -100
mesh.scale.set(2,2,2)
mesh.rotation.y = Math.PI / 4
mesh.rotation.y = Math.PI * 5 / 4

Unit Circle

mesh.rotation.y = THREE.Math.degToRad(45);

Unit Circle

mesh.position.x = Math.cos( time );
mesh.position.y = Math.sin( time );

Cameras

cam = new THREE.PerspectiveCamera( fov, aspect, near, far )
cam = new THREE.PerspectiveCamera( fov, aspect, near, far )
cam = new THREE.PerspectiveCamera( fov, aspect, near, far )
camera.fov = 15
camera.fov = 60
camera.far = 1000
camera.far = 3000
camera = new THREE.OrthographicCamera( left, right, top, bottom, near, far );

Camera Controls

/three.js/examples/js/controls/OrbitControls.js

<script src="path/to/OrbitControls.js"></script>
controls = new THREE.OrbitControls( camera );
function render() {
  requestAnimationFrame( render );
  controls.update();
  renderer.render( scene, camera );
}
controls.enablePan = false;
controls.enableZoom = false;
controls.enableRotate = false;
controls.minDistance
controls.maxDistance
controls.minPolarAngle
controls.maxPolarAngle

Geometry

Geometry

var geo = new THREE.BoxGeometry( width, height, depth );
var geo = new THREE.SphereGeometry( 60, 24, 16 );
var geo = new THREE.CylinderGeometry( ... );
var geo = new THREE.TorusGeometry( ... );

Materials

Materials

var material = new THREE.MeshBasicMaterial({ ... });
var material = new THREE.MeshLambertMaterial({ ... });
var material = new THREE.MeshPhongMaterial({ ... });
var material = new THREE.MeshNormalMaterial({ ... });
var material = new THREE.MeshNormalMaterial({ ... });

Material Properties

shading: THREE.SmoothShading
shading: THREE.FlatShading
shading: THREE.FlatShading // face normals
shading: THREE.FlatShading // face normals
shading: THREE.SmoothShading // vertex normals
color: 0xaaaaaa
color: 0x3794cf
shininess: 40
shininess: 80
wireframe: true
transparent: true, opacity: 0.5

UVs

Texture Mapping

var loader = new THREE.TextureLoader();
var texture = loader.load("color-map.jpg");
map: texture
normalMap: texture
specularMap: texture
map: colorMap, specularMap: specMap, normalMap: normalMap
var material = new THREE.MeshPhongMaterial({
  color: 0xaaaaaa,
  specular: 0x333333,
  shininess: 15,
  map: colorMap,
  specularMap: specMap,
  normalMap: normalMap
});

Lights

Lights

light = new THREE.DirectionalLight( 0xdddddd, 0.8 );
light.position.set( -80, 80, 80 );
light.position.x = 80;
light.target.position = 160;
light.position.x = -80;
light = new THREE.DirectionalLight( 0xdddddd, 0.8 );
light = new THREE.DirectionalLight( 0xb4e7f2, 0.8 );
light = new THREE.DirectionalLight( 0xb4e7f2, 0.2 );
light = new THREE.DirectionalLight( 0xb4e7f2, 1.5 );
light = new THREE.DirectionalLight( 0xb4e7f2, 0.8 );
light = new THREE.PointLight( 0xb4e7f2, 0.8 );
light = new THREE.PointLight( 0xb4e7f2, 0.8 );
light = new THREE.SpotLight( 0xb4e7f2, 0.8 );
light.angle = Math.PI / 9;
light.angle = Math.PI / 5;
light.penumbra = 0.4;
light.penumbra = 0;
light.penumbra = 0.8;
light = new THREE.AmbientLight( 0x444444 );
light = new THREE.AmbientLight( 0x000000 );
light = new THREE.AmbientLight( 0x444444 );

Three Point Lighting

Key, Fill, Rim
Key, Fill, Rim

Model Converter

OBJ to JSON converter python tool
/three.js/utils/converters/obj/convert_obj_three.py

python convert_obj_three.py -i teapot.obj -o teapot.js

Model Loader

var loader = new THREE.JSONLoader();
loader.load("teapot.js", function( geometry, materials ) {
  material = new THREE.MultiMaterial( materials );
  mesh = new THREE.Mesh( geometry, material );
  scene.add( mesh );
});

Interaction

// normalized device coordinates
mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;
raycaster = new THREE.Raycaster();
var vector = new THREE.Vector3( mouse.x, mouse.y, 1 ).unproject( camera );
raycaster.set( camera.position, vector.sub( camera.position ).normalize() );
var intersects = raycaster.intersectObjects( scene.children );
INTERSECTED = intersects[ 0 ].object;


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