@babylonjs/core/Shaders/ShadersInclude/importanceSampling.js

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// Do not edit.
import { ShaderStore } from "../../Engines/shaderStore.js";
const name = "importanceSampling";
const shader = `vec3 hemisphereCosSample(vec2 u) {float phi=2.*PI*u.x;float cosTheta2=1.-u.y;float cosTheta=sqrt(cosTheta2);float sinTheta=sqrt(1.-cosTheta2);return vec3(sinTheta*cos(phi),sinTheta*sin(phi),cosTheta);}
vec3 hemisphereImportanceSampleDggx(vec2 u,float a) {float phi=2.*PI*u.x;float cosTheta2=(1.-u.y)/(1.+(a+1.)*((a-1.)*u.y));float cosTheta=sqrt(cosTheta2);float sinTheta=sqrt(1.-cosTheta2);return vec3(sinTheta*cos(phi),sinTheta*sin(phi),cosTheta);}
vec3 hemisphereImportanceSampleDggxAnisotropic(vec2 Xi,float alphaTangent,float alphaBitangent)
{alphaTangent=max(alphaTangent,0.0001);alphaBitangent=max(alphaBitangent,0.0001);float phi=atan(alphaBitangent/alphaTangent*tan(2.0*3.14159265*Xi.x));if (Xi.x>0.5) phi+=3.14159265; 
float cosPhi=cos(phi);float sinPhi=sin(phi);float alpha2=(cosPhi*cosPhi)/(alphaTangent*alphaTangent) +
(sinPhi*sinPhi)/(alphaBitangent*alphaBitangent);float tanTheta2=Xi.y/(1.0-Xi.y)/alpha2;float cosTheta=1.0/sqrt(1.0+tanTheta2);float sinTheta=sqrt(max(0.0,1.0-cosTheta*cosTheta));return vec3(sinTheta*cosPhi,sinTheta*sinPhi,cosTheta);}
vec3 hemisphereImportanceSampleDCharlie(vec2 u,float a) { 
float phi=2.*PI*u.x;float sinTheta=pow(u.y,a/(2.*a+1.));float cosTheta=sqrt(1.-sinTheta*sinTheta);return vec3(sinTheta*cos(phi),sinTheta*sin(phi),cosTheta);}`;
// Sideeffect
if (!ShaderStore.IncludesShadersStore[name]) {
    ShaderStore.IncludesShadersStore[name] = shader;
}
/** @internal */
export const importanceSampling = { name, shader };
//# sourceMappingURL=importanceSampling.js.map