131 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			131 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| import {
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| 	Mesh,
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| 	ShaderMaterial,
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| 	SphereGeometry
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| } from 'three';
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| 
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| class LightProbeHelper extends Mesh {
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| 
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| 	constructor( lightProbe, size ) {
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| 
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| 		const material = new ShaderMaterial( {
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| 
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| 			type: 'LightProbeHelperMaterial',
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| 
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| 			uniforms: {
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| 
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| 				sh: { value: lightProbe.sh.coefficients }, // by reference
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| 
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| 				intensity: { value: lightProbe.intensity }
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| 
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| 			},
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| 
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| 			vertexShader: [
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| 
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| 				'varying vec3 vNormal;',
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| 
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| 				'void main() {',
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| 
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| 				'	vNormal = normalize( normalMatrix * normal );',
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| 
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| 				'	gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );',
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| 
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| 				'}',
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| 
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| 			].join( '\n' ),
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| 
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| 			fragmentShader: [
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| 
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| 				'#define RECIPROCAL_PI 0.318309886',
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| 
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| 				'vec3 inverseTransformDirection( in vec3 normal, in mat4 matrix ) {',
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| 
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| 				'	// matrix is assumed to be orthogonal',
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| 
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| 				'	return normalize( ( vec4( normal, 0.0 ) * matrix ).xyz );',
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| 
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| 				'}',
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| 
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| 				'// source: https://graphics.stanford.edu/papers/envmap/envmap.pdf',
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| 				'vec3 shGetIrradianceAt( in vec3 normal, in vec3 shCoefficients[ 9 ] ) {',
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| 
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| 				'	// normal is assumed to have unit length',
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| 
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| 				'	float x = normal.x, y = normal.y, z = normal.z;',
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| 
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| 				'	// band 0',
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| 				'	vec3 result = shCoefficients[ 0 ] * 0.886227;',
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| 
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| 				'	// band 1',
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| 				'	result += shCoefficients[ 1 ] * 2.0 * 0.511664 * y;',
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| 				'	result += shCoefficients[ 2 ] * 2.0 * 0.511664 * z;',
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| 				'	result += shCoefficients[ 3 ] * 2.0 * 0.511664 * x;',
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| 
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| 				'	// band 2',
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| 				'	result += shCoefficients[ 4 ] * 2.0 * 0.429043 * x * y;',
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| 				'	result += shCoefficients[ 5 ] * 2.0 * 0.429043 * y * z;',
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| 				'	result += shCoefficients[ 6 ] * ( 0.743125 * z * z - 0.247708 );',
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| 				'	result += shCoefficients[ 7 ] * 2.0 * 0.429043 * x * z;',
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| 				'	result += shCoefficients[ 8 ] * 0.429043 * ( x * x - y * y );',
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| 
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| 				'	return result;',
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| 
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| 				'}',
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| 
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| 				'uniform vec3 sh[ 9 ]; // sh coefficients',
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| 
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| 				'uniform float intensity; // light probe intensity',
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| 
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| 				'varying vec3 vNormal;',
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| 
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| 				'void main() {',
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| 
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| 				'	vec3 normal = normalize( vNormal );',
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| 
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| 				'	vec3 worldNormal = inverseTransformDirection( normal, viewMatrix );',
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| 
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| 				'	vec3 irradiance = shGetIrradianceAt( worldNormal, sh );',
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| 
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| 				'	vec3 outgoingLight = RECIPROCAL_PI * irradiance * intensity;',
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| 
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| 				'	gl_FragColor = linearToOutputTexel( vec4( outgoingLight, 1.0 ) );',
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| 
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| 				'}'
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| 
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| 			].join( '\n' )
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| 
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| 		} );
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| 
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| 		const geometry = new SphereGeometry( 1, 32, 16 );
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| 
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| 		super( geometry, material );
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| 
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| 		this.lightProbe = lightProbe;
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| 		this.size = size;
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| 		this.type = 'LightProbeHelper';
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| 
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| 		this.onBeforeRender();
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| 
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| 	}
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| 
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| 	dispose() {
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| 
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| 		this.geometry.dispose();
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| 		this.material.dispose();
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| 
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| 	}
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| 
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| 	onBeforeRender() {
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| 
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| 		this.position.copy( this.lightProbe.position );
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| 
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| 		this.scale.set( 1, 1, 1 ).multiplyScalar( this.size );
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| 
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| 		this.material.uniforms.intensity.value = this.lightProbe.intensity;
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| 
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| 	}
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| 
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| }
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| 
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| export { LightProbeHelper };
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