animate/webGl/my-threejs-test/node_modules/three/examples/jsm/shaders/SubsurfaceScatteringShader.js

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2024-06-24 09:24:00 +00:00
import {
Color,
ShaderChunk,
ShaderLib,
UniformsUtils
} from 'three';
/**
* ------------------------------------------------------------------------------------------
* Subsurface Scattering shader
* Based 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/
*------------------------------------------------------------------------------------------
*/
function replaceAll( string, find, replace ) {
return string.split( find ).join( replace );
}
const meshphong_frag_head = ShaderChunk[ 'meshphong_frag' ].slice( 0, ShaderChunk[ 'meshphong_frag' ].indexOf( 'void main() {' ) );
const meshphong_frag_body = ShaderChunk[ 'meshphong_frag' ].slice( ShaderChunk[ 'meshphong_frag' ].indexOf( 'void main() {' ) );
const SubsurfaceScatteringShader = {
name: 'SubsurfaceScatteringShader',
uniforms: UniformsUtils.merge( [
ShaderLib[ 'phong' ].uniforms,
{
'thicknessMap': { value: null },
'thicknessColor': { value: new Color( 0xffffff ) },
'thicknessDistortion': { value: 0.1 },
'thicknessAmbient': { value: 0.0 },
'thicknessAttenuation': { value: 0.1 },
'thicknessPower': { value: 2.0 },
'thicknessScale': { value: 10.0 }
}
] ),
vertexShader: [
'#define USE_UV',
ShaderChunk[ 'meshphong_vert' ],
].join( '\n' ),
fragmentShader: [
'#define USE_UV',
'#define SUBSURFACE',
meshphong_frag_head,
'uniform sampler2D thicknessMap;',
'uniform float thicknessPower;',
'uniform float thicknessScale;',
'uniform float thicknessDistortion;',
'uniform float thicknessAmbient;',
'uniform float thicknessAttenuation;',
'uniform vec3 thicknessColor;',
'void RE_Direct_Scattering(const in IncidentLight directLight, const in vec2 uv, const in vec3 geometryPosition, const in vec3 geometryNormal, const in vec3 geometryViewDir, const in vec3 geometryClearcoatNormal, inout ReflectedLight reflectedLight) {',
' vec3 thickness = thicknessColor * texture2D(thicknessMap, uv).r;',
' vec3 scatteringHalf = normalize(directLight.direction + (geometryNormal * thicknessDistortion));',
' float scatteringDot = pow(saturate(dot(geometryViewDir, -scatteringHalf)), thicknessPower) * thicknessScale;',
' vec3 scatteringIllu = (scatteringDot + thicknessAmbient) * thickness;',
' reflectedLight.directDiffuse += scatteringIllu * thicknessAttenuation * directLight.color;',
'}',
meshphong_frag_body.replace( '#include <lights_fragment_begin>',
replaceAll(
ShaderChunk[ 'lights_fragment_begin' ],
'RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );',
[
'RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );',
'#if defined( SUBSURFACE ) && defined( USE_UV )',
' RE_Direct_Scattering(directLight, vUv, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, reflectedLight);',
'#endif',
].join( '\n' )
),
),
].join( '\n' ),
};
export { SubsurfaceScatteringShader };