matcap

GLSL

by jmcjc5u

HTML

<div id="info">
  MatCap Example
</div>
<script src="https://threejs.org/build/three.min.js"></script>
<script src="https://threejs.org/examples/js/controls/OrbitControls.js"></script>
<script src="https://raw.githack.com/mrdoob/three.js/dev/examples/js/geometries/TeapotGeometry.js"> </script>

<script type="x-shader/x-vertex" id="sem-vs">

	varying vec2 vN;

	void main() {

		vec3 e = normalize( vec3( modelViewMatrix * vec4( position, 1.0 ) ) );
		vec3 n = normalize( normalMatrix * normal );

		vec3 r = reflect( e, n );
		float m = 2. * sqrt( pow( r.x, 2. ) + pow( r.y, 2. ) + pow( r.z + 1., 2. ) );
		vN = r.xy / m + .5;

		gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1. );

	}

</script>

<script type="x-shader/x-vertex" id="sem-fs">
	
	uniform sampler2D tMatCap;

	varying vec2 vN;

	void main() {
		
		vec3 base = texture2D( tMatCap, vN ).rgb;
		gl_FragColor = vec4( base, 0.24 );

	}
	
</script>
<script src="https://code.jquery.com/jquery-2.1.4.min.js"></script>

CSS

#info {
  position: absolute;
  top: 2%;
  width: 100%;
  padding: 10px;
  text-align: center;
  color: #ffff00
}

body {
  overflow: hidden;
}

JavaScript

var scene, renderer, camera;
var matcapMaterial;

init();
animate();

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

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

  scene = new THREE.Scene();

  camera = new THREE.PerspectiveCamera(45, width / height, 1, 10000);
  camera.position.z = 200;
  camera.lookAt(new THREE.Vector3(0, 0, 0));

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

  var gridXZ = new THREE.GridHelper(200, 20, 'red','white');
  scene.add(gridXZ);

	//////////////////////////////////////////////////////////////////////
	var loader = new THREE.TextureLoader();
  loader.setCrossOrigin ('');
  var matcap = loader.load ('https://i.imgur.com/eyCHL7L.jpg');
  
  var matcapMaterial = new THREE.ShaderMaterial( {
    //transparent: true,
    side: THREE.DoubleSide,
		uniforms: { 
			tMatCap: { type: 't', value: matcap} 
		},
		vertexShader: document.getElementById( 'sem-vs' ).textContent,
		fragmentShader: document.getElementById( 'sem-fs' ).textContent,
		shading: THREE.SmoothShading
		
	} );
  
  var geometry = new THREE.TeapotGeometry();
 	var teapotMesh = new THREE.Mesh(geometry, matcapMaterial);
  teapotMesh.scale.set (.21,.21,.21);
  teapotMesh.position.set (20,10,0);
  
  scene.add (teapotMesh);

	let torusKnot = new THREE.Mesh (new THREE.TorusKnotGeometry(), matcapMaterial);
  torusKnot.scale.set (10,10,10);
  torusKnot.position.set (-20,10,20);
  scene.add (torusKnot);
}

function animate() {
  requestAnimationFrame(animate);
  renderer.render(scene, camera);
}