Doodle3D-Slicer/three.js-master/examples/js/shaders/FresnelShader.js
2015-06-12 15:58:26 +02:00

75 lines
2.1 KiB
JavaScript
Executable File

/**
* @author alteredq / http://alteredqualia.com/
*
* Based on Nvidia Cg tutorial
*/
THREE.FresnelShader = {
uniforms: {
"mRefractionRatio": { type: "f", value: 1.02 },
"mFresnelBias": { type: "f", value: 0.1 },
"mFresnelPower": { type: "f", value: 2.0 },
"mFresnelScale": { type: "f", value: 1.0 },
"tCube": { type: "t", value: null }
},
vertexShader: [
"uniform float mRefractionRatio;",
"uniform float mFresnelBias;",
"uniform float mFresnelScale;",
"uniform float mFresnelPower;",
"varying vec3 vReflect;",
"varying vec3 vRefract[3];",
"varying float vReflectionFactor;",
"void main() {",
"vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );",
"vec4 worldPosition = modelMatrix * vec4( position, 1.0 );",
"vec3 worldNormal = normalize( mat3( modelMatrix[0].xyz, modelMatrix[1].xyz, modelMatrix[2].xyz ) * normal );",
"vec3 I = worldPosition.xyz - cameraPosition;",
"vReflect = reflect( I, worldNormal );",
"vRefract[0] = refract( normalize( I ), worldNormal, mRefractionRatio );",
"vRefract[1] = refract( normalize( I ), worldNormal, mRefractionRatio * 0.99 );",
"vRefract[2] = refract( normalize( I ), worldNormal, mRefractionRatio * 0.98 );",
"vReflectionFactor = mFresnelBias + mFresnelScale * pow( 1.0 + dot( normalize( I ), worldNormal ), mFresnelPower );",
"gl_Position = projectionMatrix * mvPosition;",
"}"
].join("\n"),
fragmentShader: [
"uniform samplerCube tCube;",
"varying vec3 vReflect;",
"varying vec3 vRefract[3];",
"varying float vReflectionFactor;",
"void main() {",
"vec4 reflectedColor = textureCube( tCube, vec3( -vReflect.x, vReflect.yz ) );",
"vec4 refractedColor = vec4( 1.0 );",
"refractedColor.r = textureCube( tCube, vec3( -vRefract[0].x, vRefract[0].yz ) ).r;",
"refractedColor.g = textureCube( tCube, vec3( -vRefract[1].x, vRefract[1].yz ) ).g;",
"refractedColor.b = textureCube( tCube, vec3( -vRefract[2].x, vRefract[2].yz ) ).b;",
"gl_FragColor = mix( refractedColor, reflectedColor, clamp( vReflectionFactor, 0.0, 1.0 ) );",
"}"
].join("\n")
};