LightProbeHelper constructor

LightProbeHelper(LightProbe lightProbe, double size)

Implementation

factory LightProbeHelper(LightProbe lightProbe, double size){
	final material = ShaderMaterial.fromMap( {
		//'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' )
	});

	final geometry = SphereGeometry( 1, 32, 16 );
    final lph = LightProbeHelper.create(geometry, material,lightProbe,size);

    return lph;
}