Accueil / npm / three@0.186.1 / examples / jsm / helpers / LightProbeHelper.js
LightProbeHelper.js
import {
Mesh,
ShaderMaterial,
SphereGeometry
} from 'three';
/**
* Renders a sphere to visualize a light probe in the scene.
*
* This helper can only be used with {@link WebGLRenderer}.
* When using {@link WebGPURenderer}, import from `LightProbeHelperGPU.js`.
*
* ```js
* const helper = new LightProbeHelper( lightProbe );
* scene.add( helper );
* ```
*
* @augments Mesh
* @three_import import { LightProbeHelper } from 'three/addons/helpers/LightProbeHelper.js';
*/
class LightProbeHelper extends Mesh {
/**
* Constructs a new light probe helper.
*
* @param {LightProbe} lightProbe - The light probe to visualize.
* @param {number} [size=1] - The size of the helper.
*/
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 transformNormalByInverseViewMatrix( in vec3 normal, in mat4 viewMatrix ) {
// upper-left 3x3 of view matrix is assumed to be orthogonal
return normalize( ( vec4( normal, 0.0 ) * viewMatrix ).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 = transformNormalByInverseViewMatrix( 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 );
/**
* The light probe to visualize.
*
* @type {LightProbe}
*/
this.lightProbe = lightProbe;
/**
* The size of the helper.
*
* @type {number}
* @default 1
*/
this.size = size;
this.type = 'LightProbeHelper';
this.onBeforeRender();
}
/**
* Frees the GPU-related resources allocated by this instance. Call this
* method whenever this instance is no longer used in your app.
*/
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 };