( function () {
class LightProbeHelper extends THREE.Mesh {
constructor( lightProbe, size ) {
const material = new THREE.ShaderMaterial( {
type: 'LightProbeHelperMaterial',
uniforms: {
sh: {
value: lightProbe.sh.coefficients
},
// by reference
intensity: {
value: lightProbe.intensity
}
},
vertexShader: [ 'varying vec3 vNormal;', 'void main() {', ' vNormal = normalize( normalMatrix * normal );', ' gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );', '}' ].join( '\n' ),
fragmentShader: [ '#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 ) );', '}' ].join( '\n' )
} );
const geometry = new THREE.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;
}
}
THREE.LightProbeHelper = LightProbeHelper;
} )();
