ShaderMaterial Shading

by Perry Keh

HTML

<div id="info">GLSL Shading</div>
<script src="http://cdnjs.cloudflare.com/ajax/libs/three.js/r70/three.min.js"></script>
<script src="https://dl.dropboxusercontent.com/u/3587259/Code/Threejs/OrbitControls.js">
    
</script>
<script id="myVertexShader" type="x-shader/x-vertex">
    uniform vec3 lightpos;
    varying vec3 eyelightdir;
    varying vec3 eyenormal;
    
    varying vec4 eyepos;
    
    void main() {
        // input: position (vec3, object coordinate)
        //        uv (vec2, texture coordinate)
        //        normal (vec3, object normal)
        // output: gl_Position (vec4) clip coordinate
        gl_Position = projectionMatrix * modelViewMatrix * vec4(position, 1.0);
        
        eyepos = modelViewMatrix * vec4 (lightpos, 1.0);
        vec4 eyelightpos = viewMatrix * vec4 (lightpos, 1.0);
        eyelightdir = normalize (eyelightpos.xyz - eyepos.xyz);
        eyenormal = normalMatrix * normal;
    }
</script>
<script id="myFragmentShader" type="x-shader/x-fragment">
    varying vec3 eyelightdir;
    varying vec3 eyelightdir2;
    varying vec3 eyenormal;
    
    varying vec4 eyepos;
    void main() {
        // output: gl_FragColor (vec4, rgba)
    float intensity = dot (normalize (eyenormal),normalize(eyelightdir)); 
    vec3 diffuse = intensity*vec3(1,1,1);
    vec3 h = normalize(-normalize(eyepos.xyz) + normalize(eyelightdir));
    float shininess = 40.;
    vec3 specular = pow(dot(eyenormal,h),shininess)*vec3(1,0,0);
    gl_FragColor = vec4(diffuse + specular, 1.0);
    }
</script>

CSS

body {
    background-color: #fff;
    color: #111;
    margin: 0px;
    overflow: hidden;
    font-family: Monospace;
    font-size: 10px;
    position: absolute;
}
#info {
    position: absolute;
    top: 0px;
    width: 100%;
    padding: 5px;
    text-align: center;
    color: #ffff00
}

JavaScript

var scene, renderer, camera;
var mesh, angle = 0;
var controls;
var pointLight, lightSphere;

var meshMaterial;

init();
animate();

function init() {
    var width = window.innerWidth;
    var height = window.innerHeight;

    renderer = new THREE.WebGLRenderer({
        antialias: true
    });
    renderer.setSize(width, height);
    document.body.appendChild(renderer.domElement);
    renderer.setClearColor(0x888888);

    scene = new THREE.Scene();

    camera = new THREE.PerspectiveCamera(45, width / height, 0.1, 10000);
    camera.position.y = 160;
    camera.position.z = 400;
    camera.lookAt(new THREE.Vector3(0, 0, 0));

    controls = new THREE.OrbitControls(camera, renderer.domElement);

    var gridXZ = new THREE.GridHelper(100, 10);
    gridXZ.setColors(new THREE.Color(0xff0000), new THREE.Color(0xffffff));
    scene.add(gridXZ);

    pointLight = new THREE.PointLight(0xffffff);
    scene.add(pointLight);
    lightSphere = new THREE.Mesh(new THREE.SphereGeometry(5),
    new THREE.MeshBasicMaterial({
        color: 0xff0000,
       
        wireframe: true
    }));
    scene.add(lightSphere);

    var ambientLight = new THREE.AmbientLight(0x111111);
    scene.add(ambientLight);

    meshMaterial = new THREE.ShaderMaterial({
        uniforms: {
            lightpos: {type: 'v3', value: new THREE.Vector3()}
        },
        vertexShader: document.getElementById('myVertexShader').textContent,
        fragmentShader: document.getElementById('myFragmentShader').textContent
    });

    var geometry = new THREE.TorusKnotGeometry(20, 5, 100, 16);
    mesh = new THREE.Mesh(geometry, meshMaterial);
    //mesh.position.set(70,0,50);
    mesh.rotation.y = Math.PI/2;
    scene.add(mesh);
}

function animate() {
    angle += 0.01;
    pointLight.position.set(80 * Math.cos(angle), 80, 80 * Math.sin(angle));
    lightSphere.position.copy(pointLight.position);
    meshMaterial.uniforms.lightpos.value.copy(pointLight.position);

    requestAnimationFrame(animate);
  ...