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- /**
- * Based on Nvidia Cg tutorial
- */
- var FresnelShader = {
- uniforms: {
- 'mRefractionRatio': { value: 1.02 },
- 'mFresnelBias': { value: 0.1 },
- 'mFresnelPower': { value: 2.0 },
- 'mFresnelScale': { value: 1.0 },
- 'tCube': { 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' )
- };
- export { FresnelShader };
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