mirror of
https://github.com/Doodle3D/Doodle3D-Slicer.git
synced 2024-08-23 22:00:42 +02:00
183 lines
5.1 KiB
JavaScript
183 lines
5.1 KiB
JavaScript
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// Parallax Occlusion shaders from
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// http://sunandblackcat.com/tipFullView.php?topicid=28
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// No tangent-space transforms logic based on
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// http://mmikkelsen3d.blogspot.sk/2012/02/parallaxpoc-mapping-and-no-tangent.html
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THREE.ParallaxShader = {
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// Ordered from fastest to best quality.
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modes: {
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none: 'NO_PARALLAX',
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basic: 'USE_BASIC_PARALLAX',
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steep: 'USE_STEEP_PARALLAX',
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occlusion: 'USE_OCLUSION_PARALLAX', // a.k.a. POM
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relief: 'USE_RELIEF_PARALLAX',
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},
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uniforms: {
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"bumpMap": { type: "t", value: null },
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"map": { type: "t", value: null },
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"parallaxScale": { type: "f", value: null },
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"parallaxMinLayers": { type: "f", value: null },
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"parallaxMaxLayers": { type: "f", value: null }
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},
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vertexShader: [
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"varying vec2 vUv;",
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"varying vec3 vViewPosition;",
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"varying vec3 vNormal;",
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"void main() {",
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"vUv = uv;",
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"vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );",
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"vViewPosition = -mvPosition.xyz;",
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"vNormal = normalize( normalMatrix * normal );",
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"gl_Position = projectionMatrix * mvPosition;",
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"}"
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].join( "\n" ),
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fragmentShader: [
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"uniform sampler2D bumpMap;",
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"uniform sampler2D map;",
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"uniform float parallaxScale;",
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"uniform float parallaxMinLayers;",
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"uniform float parallaxMaxLayers;",
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"varying vec2 vUv;",
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"varying vec3 vViewPosition;",
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"varying vec3 vNormal;",
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"#ifdef USE_BASIC_PARALLAX",
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"vec2 parallaxMap( in vec3 V ) {",
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"float initialHeight = texture2D( bumpMap, vUv ).r;",
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// No Offset Limitting: messy, floating output at grazing angles.
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//"vec2 texCoordOffset = parallaxScale * V.xy / V.z * initialHeight;",
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// Offset Limiting
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"vec2 texCoordOffset = parallaxScale * V.xy * initialHeight;",
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"return vUv - texCoordOffset;",
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"}",
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"#else",
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"vec2 parallaxMap( in vec3 V ) {",
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// Determine number of layers from angle between V and N
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"float numLayers = mix( parallaxMaxLayers, parallaxMinLayers, abs( dot( vec3( 0.0, 0.0, 1.0 ), V ) ) );",
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"float layerHeight = 1.0 / numLayers;",
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"float currentLayerHeight = 0.0;",
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// Shift of texture coordinates for each iteration
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"vec2 dtex = parallaxScale * V.xy / V.z / numLayers;",
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"vec2 currentTextureCoords = vUv;",
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"float heightFromTexture = texture2D( bumpMap, currentTextureCoords ).r;",
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// while ( heightFromTexture > currentLayerHeight )
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"for ( int i = 0; i == 0; i += 0 ) {",
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"if ( heightFromTexture <= currentLayerHeight ) {",
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"break;",
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"}",
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"currentLayerHeight += layerHeight;",
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// Shift texture coordinates along vector V
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"currentTextureCoords -= dtex;",
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"heightFromTexture = texture2D( bumpMap, currentTextureCoords ).r;",
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"}",
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"#ifdef USE_STEEP_PARALLAX",
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"return currentTextureCoords;",
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"#elif defined( USE_RELIEF_PARALLAX )",
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"vec2 deltaTexCoord = dtex / 2.0;",
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"float deltaHeight = layerHeight / 2.0;",
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// Return to the mid point of previous layer
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"currentTextureCoords += deltaTexCoord;",
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"currentLayerHeight -= deltaHeight;",
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// Binary search to increase precision of Steep Parallax Mapping
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"const int numSearches = 5;",
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"for ( int i = 0; i < numSearches; i += 1 ) {",
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"deltaTexCoord /= 2.0;",
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"deltaHeight /= 2.0;",
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"heightFromTexture = texture2D( bumpMap, currentTextureCoords ).r;",
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// Shift along or against vector V
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"if( heightFromTexture > currentLayerHeight ) {", // Below the surface
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"currentTextureCoords -= deltaTexCoord;",
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"currentLayerHeight += deltaHeight;",
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"} else {", // above the surface
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"currentTextureCoords += deltaTexCoord;",
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"currentLayerHeight -= deltaHeight;",
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"}",
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"}",
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"return currentTextureCoords;",
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"#elif defined( USE_OCLUSION_PARALLAX )",
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"vec2 prevTCoords = currentTextureCoords + dtex;",
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// Heights for linear interpolation
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"float nextH = heightFromTexture - currentLayerHeight;",
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"float prevH = texture2D( bumpMap, prevTCoords ).r - currentLayerHeight + layerHeight;",
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// Proportions for linear interpolation
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"float weight = nextH / ( nextH - prevH );",
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// Interpolation of texture coordinates
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"return prevTCoords * weight + currentTextureCoords * ( 1.0 - weight );",
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"#else", // NO_PARALLAX
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"return vUv;",
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"#endif",
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"}",
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"#endif",
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"vec2 perturbUv( vec3 surfPosition, vec3 surfNormal, vec3 viewPosition ) {",
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"vec2 texDx = dFdx( vUv );",
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"vec2 texDy = dFdy( vUv );",
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"vec3 vSigmaX = dFdx( surfPosition );",
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"vec3 vSigmaY = dFdy( surfPosition );",
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"vec3 vR1 = cross( vSigmaY, surfNormal );",
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"vec3 vR2 = cross( surfNormal, vSigmaX );",
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"float fDet = dot( vSigmaX, vR1 );",
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"vec2 vProjVscr = ( 1.0 / fDet ) * vec2( dot( vR1, viewPosition ), dot( vR2, viewPosition ) );",
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"vec3 vProjVtex;",
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"vProjVtex.xy = texDx * vProjVscr.x + texDy * vProjVscr.y;",
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"vProjVtex.z = dot( surfNormal, viewPosition );",
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"return parallaxMap( vProjVtex );",
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"}",
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"void main() {",
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"vec2 mapUv = perturbUv( -vViewPosition, normalize( vNormal ), normalize( vViewPosition ) );",
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"gl_FragColor = texture2D( map, mapUv );",
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"}",
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].join( "\n" )
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};
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