Subsurface scattering support in Blinn-Phong material

examples/js/ShaderTranslucent.js

@@ -0,0 +1,206 @@
+/**
+ * @author daoshengmu / http://dsmu.me/
+ *
+ */
+
+
+THREE.TranslucentShader = function TranslucentShader() {
+
+	/* ------------------------------------------------------------------------------------------
+	//	Subsurface Scattering shader
+	// 		- Base on GDC 2011 – Approximating Translucency for a Fast, Cheap and Convincing Subsurface Scattering Look
+	// 			https://colinbarrebrisebois.com/2011/03/07/gdc-2011-approximating-translucency-for-a-fast-cheap-and-convincing-subsurface-scattering-look/
+	// ------------------------------------------------------------------------------------------ */
+
+	this.uniforms = THREE.UniformsUtils.merge( [
+
+		THREE.UniformsLib[ "common" ],
+		THREE.UniformsLib[ "lights" ],
+
+		{
+			"color":  { value: new THREE.Color( 0xffffff ) },
+			"diffuse":  { value: new THREE.Color( 0xffffff ) },
+			"specular": { value: new THREE.Color( 0xffffff ) },
+			"emissive": { value: new THREE.Color( 0x000000 ) },
+			"opacity": { value: 1 },
+			"shininess": { value: 1 },
+
+			"thicknessMap": { value: null },
+			"thicknessColor": { value: new THREE.Color( 0xffffff ) },
+			"thicknessDistortion": { value: 0.1 },
+			"thicknessAmbient": { value: 0.0 },
+			"thicknessAttenuation": { value: 0.1 },
+			"thicknessPower": { value: 2.0 },
+			"thicknessScale": { value: 10.0 }
+		}
+
+	] );
+
+	this.fragmentShader = [
+		"#define USE_MAP",
+		"#define PHONG",
+		"#define TRANSLUCENT",
+		"#include <common>",
+		"#include <bsdfs>",
+		"#include <uv_pars_fragment>",
+		"#include <map_pars_fragment>",
+		"#include <lights_phong_pars_fragment>",
+
+		"varying vec3 vColor;",
+
+		"uniform vec3 diffuse;",
+		"uniform vec3 specular;",
+		"uniform vec3 emissive;",
+		"uniform float opacity;",
+		"uniform float shininess;",
+
+		// Translucency
+		"uniform sampler2D thicknessMap;",
+		"uniform float thicknessPower;",
+		"uniform float thicknessScale;",
+		"uniform float thicknessDistortion;",
+		"uniform float thicknessAmbient;",
+		"uniform float thicknessAttenuation;",
+		"uniform vec3 thicknessColor;",
+
+		THREE.ShaderChunk[ "lights_pars_begin" ],
+
+		"void RE_Direct_Scattering(const in IncidentLight directLight, const in vec2 uv, const in GeometricContext geometry, inout ReflectedLight reflectedLight) {",
+		"	vec3 thickness = thicknessColor * texture2D(thicknessMap, uv).r;",
+		"	vec3 scatteringHalf = normalize(directLight.direction + (geometry.normal * thicknessDistortion));",
+		"	float scatteringDot = pow(saturate(dot(geometry.viewDir, -scatteringHalf)), thicknessPower) * thicknessScale;",
+		"	vec3 scatteringIllu = (scatteringDot + thicknessAmbient) * thickness;",
+		"	reflectedLight.directDiffuse += scatteringIllu * thicknessAttenuation * directLight.color;",
+		"}",
+
+		"void main() {",
+
+		"	vec3 normal = normalize( vNormal );",
+
+		"	vec3 viewerDirection = normalize( vViewPosition );",
+
+		"	vec4 diffuseColor = vec4( diffuse, opacity );",
+		"	ReflectedLight reflectedLight = ReflectedLight( vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ), vec3( 0.0 ) );",
+
+			THREE.ShaderChunk[ "map_fragment" ],
+			THREE.ShaderChunk[ "color_fragment" ],
+			THREE.ShaderChunk[ "specularmap_fragment" ],
+
+		"	vec3 totalEmissiveRadiance = emissive;",
+
+			THREE.ShaderChunk["lights_phong_fragment"],
+
+		// Doing lights fragment begin.
+		"	GeometricContext geometry;",
+		"	geometry.position = - vViewPosition;",
+		"	geometry.normal = normal;",
+		"	geometry.viewDir = normalize( vViewPosition );",
+
+		"	IncidentLight directLight;",
+
+		"	#if ( NUM_POINT_LIGHTS > 0 ) && defined( RE_Direct )",
+
+		"		PointLight pointLight;",
+
+		"		#pragma unroll_loop",
+		"		for ( int i = 0; i < NUM_POINT_LIGHTS; i ++ ) {",
+		"		 	pointLight = pointLights[ i ];",
+		"		 	getPointDirectLightIrradiance( pointLight, geometry, directLight );",
+
+		"			#ifdef USE_SHADOWMAP",
+		"			directLight.color *= all( bvec2( pointLight.shadow, directLight.visible ) ) ? getPointShadow( pointShadowMap[ i ], pointLight.shadowMapSize, pointLight.shadowBias, pointLight.shadowRadius, vPointShadowCoord[ i ], pointLight.shadowCameraNear, pointLight.shadowCameraFar ) : 1.0;",
+		"			#endif",
+
+		"			RE_Direct( directLight, geometry, material, reflectedLight );",
+
+		"			#if defined( TRANSLUCENT ) && defined( USE_MAP )",
+		"			RE_Direct_Scattering(directLight, vUv, geometry, reflectedLight);",
+		"			#endif",
+		"		}",
+
+		"		#endif",
+
+		"	#if ( NUM_DIR_LIGHTS > 0 ) && defined( RE_Direct )",
+
+		"		DirectionalLight directionalLight;",
+
+		"		#pragma unroll_loop",
+		"		for ( int i = 0; i < NUM_DIR_LIGHTS; i ++ ) {",
+		"			directionalLight = directionalLights[ i ];",
+		"			getDirectionalDirectLightIrradiance( directionalLight, geometry, directLight );",
+
+		"			#ifdef USE_SHADOWMAP",
+		"			directLight.color *= all( bvec2( directionalLight.shadow, directLight.visible ) ) ? getShadow( directionalShadowMap[ i ], directionalLight.shadowMapSize, directionalLight.shadowBias, directionalLight.shadowRadius, vDirectionalShadowCoord[ i ] ) : 1.0;",
+		"			#endif",
+
+		"			RE_Direct( directLight, geometry, material, reflectedLight );",
+
+		"			#if defined( TRANSLUCENT ) && defined( USE_MAP )",
+		"			RE_Direct_Scattering(directLight, vUv, geometry, reflectedLight);",
+		"			#endif",
+		"		}",
+
+		"	#endif",
+
+		"	#if defined( RE_IndirectDiffuse )",
+
+		"		vec3 irradiance = getAmbientLightIrradiance( ambientLightColor );",
+
+		"		#if ( NUM_HEMI_LIGHTS > 0 )",
+
+		"			#pragma unroll_loop",
+		"			for ( int i = 0; i < NUM_HEMI_LIGHTS; i ++ ) {",
+
+		"				irradiance += getHemisphereLightIrradiance( hemisphereLights[ i ], geometry );",
+
+		"			}",
+
+		"		#endif",
+
+		"	#endif",
+
+		"	#if defined( RE_IndirectSpecular )",
+
+		"		vec3 radiance = vec3( 0.0 );",
+		"		vec3 clearCoatRadiance = vec3( 0.0 );",
+
+		"	#endif",
+			THREE.ShaderChunk["lights_fragment_end"],
+
+		"	vec3 outgoingLight = reflectedLight.directDiffuse + reflectedLight.indirectDiffuse + reflectedLight.directSpecular + reflectedLight.indirectSpecular + totalEmissiveRadiance;",
+		"	gl_FragColor = vec4( outgoingLight, diffuseColor.a );",	// TODO, this should be pre-multiplied to allow for bright highlights on very transparent objects
+
+			THREE.ShaderChunk["encodings_fragment"],
+
+		"}"
+
+	].join( "\n" ),
+
+	this.vertexShader = [
+
+		"varying vec3 vNormal;",
+		"varying vec2 vUv;",
+
+		"varying vec3 vViewPosition;",
+
+		THREE.ShaderChunk[ "common" ],
+
+		"void main() {",
+
+		"	vec4 worldPosition = modelMatrix * vec4( position, 1.0 );",
+
+		"	vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );",
+
+		"	vViewPosition = -mvPosition.xyz;",
+
+		"	vNormal = normalize( normalMatrix * normal );",
+
+		"	vUv = uv;",
+
+		"	gl_Position = projectionMatrix * mvPosition;",
+
+		"}",
+
+	].join( "\n" )
+
+};