Accueil / npm / three@0.171.0 / examples / jsm / helpers / LightProbeHelper.js
LightProbeHelper.js
import {
Mesh,
ShaderMaterial,
SphereGeometry
} from 'three';
class LightProbeHelper extends Mesh {
constructor( lightProbe, size = 1 ) {
const material = new ShaderMaterial( {
type: 'LightProbeHelperMaterial',
uniforms: {
sh: { value: lightProbe.sh.coefficients }, // by reference
intensity: { value: lightProbe.intensity }
},
vertexShader: /* glsl */`
varying vec3 vNormal;
void main() {
vNormal = normalize( normalMatrix * normal );
gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
}
`,
fragmentShader: /* glsl */`
#define RECIPROCAL_PI 0.318309886
vec3 inverseTransformDirection( in vec3 normal, in mat4 matrix ) {
// matrix is assumed to be orthogonal
return normalize( ( vec4( normal, 0.0 ) * matrix ).xyz );
}
// source: https://graphics.stanford.edu/papers/envmap/envmap.pdf,
vec3 shGetIrradianceAt( in vec3 normal, in vec3 shCoefficients[ 9 ] ) {
// normal is assumed to have unit length,
float x = normal.x, y = normal.y, z = normal.z;
// band 0,
vec3 result = shCoefficients[ 0 ] * 0.886227;
// band 1,
result += shCoefficients[ 1 ] * 2.0 * 0.511664 * y;
result += shCoefficients[ 2 ] * 2.0 * 0.511664 * z;
result += shCoefficients[ 3 ] * 2.0 * 0.511664 * x;
// band 2,
result += shCoefficients[ 4 ] * 2.0 * 0.429043 * x * y;
result += shCoefficients[ 5 ] * 2.0 * 0.429043 * y * z;
result += shCoefficients[ 6 ] * ( 0.743125 * z * z - 0.247708 );
result += shCoefficients[ 7 ] * 2.0 * 0.429043 * x * z;
result += shCoefficients[ 8 ] * 0.429043 * ( x * x - y * y );
return result;
}
uniform vec3 sh[ 9 ]; // sh coefficients
uniform float intensity; // light probe intensity
varying vec3 vNormal;
void main() {
vec3 normal = normalize( vNormal );
vec3 worldNormal = inverseTransformDirection( normal, viewMatrix );
vec3 irradiance = shGetIrradianceAt( worldNormal, sh );
vec3 outgoingLight = RECIPROCAL_PI * irradiance * intensity;
gl_FragColor = linearToOutputTexel( vec4( outgoingLight, 1.0 ) );
}
`,
} );
const geometry = new SphereGeometry( 1, 32, 16 );
super( geometry, material );
this.lightProbe = lightProbe;
this.size = size;
this.type = 'LightProbeHelper';
this.onBeforeRender();
}
dispose() {
this.geometry.dispose();
this.material.dispose();
}
onBeforeRender() {
this.position.copy( this.lightProbe.position );
this.scale.set( 1, 1, 1 ).multiplyScalar( this.size );
this.material.uniforms.intensity.value = this.lightProbe.intensity;
}
}
export { LightProbeHelper };