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

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// Do not edit.
import { ShaderStore } from "../../Engines/shaderStore.js";
const name = "importanceSampling";
const shader = `fn hemisphereCosSample(u: vec2f)->vec3f {var phi: f32=2.*PI*u.x;var cosTheta2: f32=1.-u.y;var cosTheta: f32=sqrt(cosTheta2);var sinTheta: f32=sqrt(1.-cosTheta2);return vec3f(sinTheta*cos(phi),sinTheta*sin(phi),cosTheta);}
fn hemisphereImportanceSampleDggx(u: vec2f,a: f32)->vec3f {var phi: f32=2.*PI*u.x;var cosTheta2: f32=(1.-u.y)/(1.+(a+1.)*((a-1.)*u.y));var cosTheta: f32=sqrt(cosTheta2);var sinTheta: f32=sqrt(1.-cosTheta2);return vec3f(sinTheta*cos(phi),sinTheta*sin(phi),cosTheta);}
fn hemisphereImportanceSampleDggxAnisotropic(Xi: vec2f,alphaTangent: f32,alphaBitangent: f32)->vec3f
{let alphaT: f32=max(alphaTangent,0.0001);let alphaB: f32=max(alphaBitangent,0.0001);var phi: f32=atan(alphaB/alphaT*tan(2.0f*PI*Xi.x));if (Xi.x>0.5) {phi+=PI; }
let cosPhi: f32=cos(phi);let sinPhi: f32=sin(phi);let alpha2: f32=(cosPhi*cosPhi)/(alphaTangent*alphaTangent) +
(sinPhi*sinPhi)/(alphaB*alphaB);let tanTheta2: f32=Xi.y/(1.0f-Xi.y)/alpha2;let cosTheta: f32=1.0f/sqrt(1.0f+tanTheta2);let sinTheta: f32=sqrt(max(0.0f,1.0f-cosTheta*cosTheta));return vec3f(sinTheta*cosPhi,sinTheta*sinPhi,cosTheta);}
fn hemisphereImportanceSampleDCharlie(u: vec2f,a: f32)->vec3f { 
var phi: f32=2.*PI*u.x;var sinTheta: f32=pow(u.y,a/(2.*a+1.));var cosTheta: f32=sqrt(1.-sinTheta*sinTheta);return vec3f(sinTheta*cos(phi),sinTheta*sin(phi),cosTheta);}`;
// Sideeffect
if (!ShaderStore.IncludesShadersStoreWGSL[name]) {
    ShaderStore.IncludesShadersStoreWGSL[name] = shader;
}
/** @internal */
export const importanceSamplingWGSL = { name, shader };
//# sourceMappingURL=importanceSampling.js.map