ShaderMaterial Shading

by yi hom

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;
   
    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);
    
    vec4 eyepos = modelViewMatrix * vec4 (position,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 eyenormal;    
    
    void main() {
        // output: gl_FragColor (vec4, rgba)
        float intensity = dot(normalize (eyenormal),normalize (eyelightdir));
        if(intensity <= 0.3)
        {
            intensity=0.0;
        }
        else if (intensity <=0.6)
        {
            intensity=0.45;
        }
        else if (intensity <=1.0)
        {
            intensity=0.9;
        }
        vec3 color = intensity*vec3(1,1,1);
        gl_FragColor = vec4(color, 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: 0xffff00,
        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);
    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);
    controls.update();
    render();
}

function render() {
...