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

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// Do not edit.
import { ShaderStore } from "../../Engines/shaderStore.js";
const name = "pbrBRDFFunctions";
const shader = `#define FRESNEL_MAXIMUM_ON_ROUGH 0.25
#define BRDF_DIFFUSE_MODEL_EON 0
#define BRDF_DIFFUSE_MODEL_BURLEY 1
#define BRDF_DIFFUSE_MODEL_LAMBERT 2
#define BRDF_DIFFUSE_MODEL_LEGACY 3
#define DIELECTRIC_SPECULAR_MODEL_GLTF 0
#define DIELECTRIC_SPECULAR_MODEL_OPENPBR 1
#define CONDUCTOR_SPECULAR_MODEL_GLTF 0
#define CONDUCTOR_SPECULAR_MODEL_OPENPBR 1
#ifndef PBR_VERTEX_SHADER
#ifdef MS_BRDF_ENERGY_CONSERVATION
fn getEnergyConservationFactor(specularEnvironmentR0: vec3f,environmentBrdf: vec3f)->vec3f {return 1.0+specularEnvironmentR0*(1.0/environmentBrdf.y-1.0);}
#endif
#if CONDUCTOR_SPECULAR_MODEL==CONDUCTOR_SPECULAR_MODEL_OPENPBR 
fn getF82Specular(NdotV: f32,F0: vec3f,edgeTint: vec3f,roughness: f32)->vec3f {const cos_theta_max: f32=0.142857143; 
const one_minus_cos_theta_max_to_the_fifth: f32=0.462664366; 
const one_minus_cos_theta_max_to_the_sixth: f32=0.396569457; 
let white_minus_F0: vec3f=vec3f(1.0f)-F0;let b_numerator: vec3f=(F0+white_minus_F0*one_minus_cos_theta_max_to_the_fifth)*(vec3f(1.0)-edgeTint);const b_denominator: f32=cos_theta_max*one_minus_cos_theta_max_to_the_sixth;const b_denominator_reciprocal: f32=1.0f/b_denominator;let b: vec3f=b_numerator*b_denominator_reciprocal; 
let cos_theta: f32=max(roughness,NdotV);let one_minus_cos_theta: f32=1.0-cos_theta;let offset_from_F0: vec3f=(white_minus_F0-b*cos_theta*one_minus_cos_theta)*pow(one_minus_cos_theta,5.0f);return clamp(F0+offset_from_F0,vec3f(0.0f),vec3f(1.0f));}
#endif
#ifdef ENVIRONMENTBRDF
fn getBRDFLookup(NdotV: f32,perceptualRoughness: f32)->vec3f {var UV: vec2f= vec2f(NdotV,perceptualRoughness);var brdfLookup: vec4f= textureSample(environmentBrdfSampler,environmentBrdfSamplerSampler,UV);
#ifdef ENVIRONMENTBRDF_RGBD
brdfLookup=vec4f(fromRGBD(brdfLookup.rgba),brdfLookup.a);
#endif
return brdfLookup.rgb;}
fn getReflectanceFromBRDFWithEnvLookup(specularEnvironmentR0: vec3f,specularEnvironmentR90: vec3f,environmentBrdf: vec3f)->vec3f {
#ifdef BRDF_V_HEIGHT_CORRELATED
var reflectance: vec3f=(specularEnvironmentR90-specularEnvironmentR0)*environmentBrdf.x+specularEnvironmentR0*environmentBrdf.y;
#else
var reflectance: vec3f=specularEnvironmentR0*environmentBrdf.x+specularEnvironmentR90*environmentBrdf.y;
#endif
return reflectance;}
fn getReflectanceFromBRDFLookup(specularEnvironmentR0: vec3f,environmentBrdf: vec3f)->vec3f {
#ifdef BRDF_V_HEIGHT_CORRELATED
var reflectance: vec3f=mix(environmentBrdf.xxx,environmentBrdf.yyy,specularEnvironmentR0);
#else
var reflectance: vec3f=specularEnvironmentR0*environmentBrdf.x+environmentBrdf.y;
#endif
return reflectance;}
#endif
/* NOT USED
#if defined(SHEEN) && defined(SHEEN_SOFTER)
fn getBRDFLookupCharlieSheen(NdotV: f32,perceptualRoughness: f32)->f32
{var c: f32=1.0-NdotV;var c3: f32=c*c*c;return 0.65584461*c3+1.0/(4.16526551+exp(-7.97291361*perceptualRoughness+6.33516894));}
#endif
*/
#if !defined(ENVIRONMENTBRDF) || defined(REFLECTIONMAP_SKYBOX) || defined(ALPHAFRESNEL)
fn getReflectanceFromAnalyticalBRDFLookup_Jones(VdotN: f32,reflectance0: vec3f,reflectance90: vec3f,smoothness: f32)->vec3f
{var weight: f32=mix(FRESNEL_MAXIMUM_ON_ROUGH,1.0,smoothness);return reflectance0+weight*(reflectance90-reflectance0)*pow5(saturate(1.0-VdotN));}
#endif
#if defined(SHEEN) && defined(ENVIRONMENTBRDF)
/**
* The sheen BRDF not containing F can be easily stored in the blue channel of the BRDF texture.
* The blue channel contains DCharlie*VAshikhmin*NdotL as a lokkup table
*/
fn getSheenReflectanceFromBRDFLookup(reflectance0: vec3f,environmentBrdf: vec3f)->vec3f {var sheenEnvironmentReflectance: vec3f=reflectance0*environmentBrdf.b;return sheenEnvironmentReflectance;}
#endif
fn fresnelSchlickGGXVec3(VdotH: f32,reflectance0: vec3f,reflectance90: vec3f)->vec3f
{return reflectance0+(reflectance90-reflectance0)*pow5(1.0-VdotH);}
fn fresnelSchlickGGX(VdotH: f32,reflectance0: f32,reflectance90: f32)->f32
{return reflectance0+(reflectance90-reflectance0)*pow5(1.0-VdotH);}
#ifdef CLEARCOAT
fn getR0RemappedForClearCoat(f0: vec3f)->vec3f {
#ifdef CLEARCOAT_DEFAULTIOR
#ifdef MOBILE
return saturateVec3(f0*(f0*0.526868+0.529324)-0.0482256);
#else
return saturateVec3(f0*(f0*(0.941892-0.263008*f0)+0.346479)-0.0285998);
#endif
#else
var s: vec3f=sqrt(f0);var t: vec3f=(uniforms.vClearCoatRefractionParams.z+uniforms.vClearCoatRefractionParams.w*s)/(uniforms.vClearCoatRefractionParams.w+uniforms.vClearCoatRefractionParams.z*s);return squareVec3(t);
#endif
}
#endif
#ifdef IRIDESCENCE
const XYZ_TO_REC709: mat3x3f= mat3x3f(
3.2404542,-0.9692660, 0.0556434,
-1.5371385, 1.8760108,-0.2040259,
-0.4985314, 0.0415560, 1.0572252
);fn getIORTfromAirToSurfaceR0(f0: vec3f)->vec3f {var sqrtF0: vec3f=sqrt(f0);return (1.+sqrtF0)/(1.-sqrtF0);}
fn getR0fromIORsVec3(iorT: vec3f,iorI: f32)->vec3f {return squareVec3((iorT- vec3f(iorI))/(iorT+ vec3f(iorI)));}
fn getR0fromIORs(iorT: f32,iorI: f32)->f32 {return square((iorT-iorI)/(iorT+iorI));}
fn evalSensitivity(opd: f32,shift: vec3f)->vec3f {var phase: f32=2.0*PI*opd*1.0e-9;const val: vec3f= vec3f(5.4856e-13,4.4201e-13,5.2481e-13);const pos: vec3f= vec3f(1.6810e+06,1.7953e+06,2.2084e+06);const vr: vec3f= vec3f(4.3278e+09,9.3046e+09,6.6121e+09);var xyz: vec3f=val*sqrt(2.0*PI*vr)*cos(pos*phase+shift)*exp(-square(phase)*vr);xyz.x+=9.7470e-14*sqrt(2.0*PI*4.5282e+09)*cos(2.2399e+06*phase+shift[0])*exp(-4.5282e+09*square(phase));xyz/=1.0685e-7;var srgb: vec3f=XYZ_TO_REC709*xyz;return srgb;}
fn evalIridescence(outsideIOR: f32,eta2: f32,cosTheta1: f32,thinFilmThickness: f32,baseF0: vec3f)->vec3f {var I: vec3f= vec3f(1.0);var iridescenceIOR: f32=mix(outsideIOR,eta2,smoothstep(0.0,0.03,thinFilmThickness));var sinTheta2Sq: f32=square(outsideIOR/iridescenceIOR)*(1.0-square(cosTheta1));var cosTheta2Sq: f32=1.0-sinTheta2Sq;if (cosTheta2Sq<0.0) {return I;}
var cosTheta2: f32=sqrt(cosTheta2Sq);var R0: f32=getR0fromIORs(iridescenceIOR,outsideIOR);var R12: f32=fresnelSchlickGGX(cosTheta1,R0,1.);var R21: f32=R12;var T121: f32=1.0-R12;var phi12: f32=0.0;if (iridescenceIOR<outsideIOR) {phi12=PI;}
var phi21: f32=PI-phi12;var baseIOR: vec3f=getIORTfromAirToSurfaceR0(clamp(baseF0,vec3f(0.0),vec3f(0.9999))); 
var R1: vec3f=getR0fromIORsVec3(baseIOR,iridescenceIOR);var R23: vec3f=fresnelSchlickGGXVec3(cosTheta2,R1, vec3f(1.));var phi23: vec3f= vec3f(0.0);if (baseIOR[0]<iridescenceIOR) {phi23[0]=PI;}
if (baseIOR[1]<iridescenceIOR) {phi23[1]=PI;}
if (baseIOR[2]<iridescenceIOR) {phi23[2]=PI;}
var opd: f32=2.0*iridescenceIOR*thinFilmThickness*cosTheta2;var phi: vec3f= vec3f(phi21)+phi23;var R123: vec3f=clamp(R12*R23,vec3f(1e-5),vec3f(0.9999));var r123: vec3f=sqrt(R123);var Rs: vec3f=(T121*T121)*R23/( vec3f(1.0)-R123);var C0: vec3f=R12+Rs;I=C0;var Cm: vec3f=Rs-T121;for (var m: i32=1; m<=2; m++)
{Cm*=r123;var Sm: vec3f=2.0*evalSensitivity( f32(m)*opd, f32(m)*phi);I+=Cm*Sm;}
return max(I, vec3f(0.0));}
#endif
fn normalDistributionFunction_TrowbridgeReitzGGX(NdotH: f32,alphaG: f32)->f32
{var a2: f32=alphaG*alphaG;var d: f32=NdotH*NdotH*(a2-1.0)+1.0;return a2/(PI*d*d);}
#ifdef SHEEN
fn normalDistributionFunction_CharlieSheen(NdotH: f32,alphaG: f32)->f32
{var invR: f32=1./alphaG;var cos2h: f32=NdotH*NdotH;var sin2h: f32=1.-cos2h;return (2.+invR)*pow(sin2h,invR*.5)/(2.*PI);}
#endif
#ifdef ANISOTROPIC
fn normalDistributionFunction_BurleyGGX_Anisotropic(NdotH: f32,TdotH: f32,BdotH: f32,alphaTB: vec2f)->f32 {var a2: f32=alphaTB.x*alphaTB.y;var v: vec3f= vec3f(alphaTB.y*TdotH,alphaTB.x *BdotH,a2*NdotH);var v2: f32=dot(v,v);var w2: f32=a2/v2;return a2*w2*w2*RECIPROCAL_PI;}
#endif
#ifdef BRDF_V_HEIGHT_CORRELATED
fn smithVisibility_GGXCorrelated(NdotL: f32,NdotV: f32,alphaG: f32)->f32 {
#ifdef MOBILE
var GGXV: f32=NdotL*(NdotV*(1.0-alphaG)+alphaG);var GGXL: f32=NdotV*(NdotL*(1.0-alphaG)+alphaG);return 0.5/(GGXV+GGXL);
#else
var a2: f32=alphaG*alphaG;var GGXV: f32=NdotL*sqrt(NdotV*(NdotV-a2*NdotV)+a2);var GGXL: f32=NdotV*sqrt(NdotL*(NdotL-a2*NdotL)+a2);return 0.5/(GGXV+GGXL);
#endif
}
#else
fn smithVisibilityG1_TrowbridgeReitzGGXFast(dot: f32,alphaG: f32)->f32
{
#ifdef MOBILE
return 1.0/(dot+alphaG+(1.0-alphaG)*dot ));
#else
var alphaSquared: f32=alphaG*alphaG;return 1.0/(dot+sqrt(alphaSquared+(1.0-alphaSquared)*dot*dot));
#endif
}
fn smithVisibility_TrowbridgeReitzGGXFast(NdotL: f32,NdotV: f32,alphaG: f32)->f32
{var visibility: f32=smithVisibilityG1_TrowbridgeReitzGGXFast(NdotL,alphaG)*smithVisibilityG1_TrowbridgeReitzGGXFast(NdotV,alphaG);return visibility;}
#endif
#ifdef ANISOTROPIC
fn smithVisibility_GGXCorrelated_Anisotropic(NdotL: f32,NdotV: f32,TdotV: f32,BdotV: f32,TdotL: f32,BdotL: f32,alphaTB: vec2f)->f32 {var lambdaV: f32=NdotL*length( vec3f(alphaTB.x*TdotV,alphaTB.y*BdotV,NdotV));var lambdaL: f32=NdotV*length( vec3f(alphaTB.x*TdotL,alphaTB.y*BdotL,NdotL));var v: f32=0.5/(lambdaV+lambdaL);return v;}
#endif
#ifdef CLEARCOAT
fn visibility_Kelemen(VdotH: f32)->f32 {return 0.25/(VdotH*VdotH); }
#endif
#ifdef SHEEN
fn visibility_Ashikhmin(NdotL: f32,NdotV: f32)->f32
{return 1./(4.*(NdotL+NdotV-NdotL*NdotV));}
/* NOT USED
#ifdef SHEEN_SOFTER
fn l(x: f32,alphaG: f32)->f32
{var oneMinusAlphaSq: f32=(1.0-alphaG)*(1.0-alphaG);var a: f32=mix(21.5473,25.3245,oneMinusAlphaSq);var b: f32=mix(3.82987,3.32435,oneMinusAlphaSq);var c: f32=mix(0.19823,0.16801,oneMinusAlphaSq);var d: f32=mix(-1.97760,-1.27393,oneMinusAlphaSq);var e: f32=mix(-4.32054,-4.85967,oneMinusAlphaSq);return a/(1.0+b*pow(x,c))+d*x+e;}
fn lambdaSheen(cosTheta: f32,alphaG: f32)->f32
{return abs(cosTheta)<0.5 ? exp(l(cosTheta,alphaG)) : exp(2.0*l(0.5,alphaG)-l(1.0-cosTheta,alphaG));}
fn visibility_CharlieSheen(NdotL: f32,NdotV: f32,alphaG: f32)->f32
{var G: f32=1.0/(1.0+lambdaSheen(NdotV,alphaG)+lambdaSheen(NdotL,alphaG));return G/(4.0*NdotV*NdotL);}
#endif
*/
#endif
const constant1_FON: f32=0.5f-2.0f/(3.0f*PI);const constant2_FON: f32=2.0f/3.0f-28.0f/(15.0f*PI);fn E_FON_approx(mu: f32,roughness: f32)->f32
{var sigma: f32=roughness; 
var mucomp: f32=1.0f-mu;var mucomp2: f32=mucomp*mucomp;const Gcoeffs: mat2x2f=mat2x2f(0.0571085289f,-0.332181442f,
0.491881867f,0.0714429953f);var GoverPi: f32=dot(Gcoeffs*vec2f(mucomp,mucomp2),vec2f(1.0f,mucomp2));return (1.0f+sigma*GoverPi)/(1.0f+constant1_FON*sigma);}
fn diffuseBRDF_EON(albedo: vec3f,roughness: f32,NdotL: f32,NdotV: f32,LdotV: f32)->vec3f
{var rho: vec3f=albedo;var sigma: f32=roughness; 
var mu_i: f32=NdotL; 
var mu_o: f32=NdotV; 
var s: f32=LdotV-mu_i*mu_o; 
var sovertF: f32=select(s,s/max(mu_i,mu_o),s>0.0f); 
var AF: f32=1.0f/(1.0f+constant1_FON*sigma); 
var f_ss: vec3f=(rho*RECIPROCAL_PI)*AF*(1.0f+sigma*sovertF); 
var EFo: f32=E_FON_approx(mu_o,sigma); 
var EFi: f32=E_FON_approx(mu_i,sigma); 
var avgEF: f32=AF*(1.0f+constant2_FON*sigma); 
var rho_ms: vec3f=(rho*rho)*avgEF/(vec3f(1.0f)-rho*(1.0f-avgEF));const eps: f32=1.0e-7f;var f_ms: vec3f=(rho_ms*RECIPROCAL_PI)*max(eps,1.0f-EFo) 
* max(eps,1.0f-EFi)
/ max(eps,1.0f-avgEF);return (f_ss+f_ms);}
fn diffuseBRDF_Burley(NdotL: f32,NdotV: f32,VdotH: f32,roughness: f32)->f32 {var diffuseFresnelNV: f32=pow5(saturateEps(1.0-NdotL));var diffuseFresnelNL: f32=pow5(saturateEps(1.0-NdotV));var diffuseFresnel90: f32=0.5+2.0*VdotH*VdotH*roughness;var fresnel: f32 =
(1.0+(diffuseFresnel90-1.0)*diffuseFresnelNL) *
(1.0+(diffuseFresnel90-1.0)*diffuseFresnelNV);return fresnel/PI;}
#ifdef SS_TRANSLUCENCY
fn transmittanceBRDF_Burley(tintColor: vec3f,diffusionDistance: vec3f,thickness: f32)->vec3f {var S: vec3f=1./maxEpsVec3(diffusionDistance);var temp: vec3f=exp((-0.333333333*thickness)*S);return tintColor.rgb*0.25*(temp*temp*temp+3.0*temp);}
fn computeWrappedDiffuseNdotL(NdotL: f32,w: f32)->f32 {var t: f32=1.0+w;var invt2: f32=1.0/(t*t);return saturate((NdotL+w)*invt2);}
#endif
#endif 
`;
// Sideeffect
if (!ShaderStore.IncludesShadersStoreWGSL[name]) {
    ShaderStore.IncludesShadersStoreWGSL[name] = shader;
}
/** @internal */
export const pbrBRDFFunctionsWGSL = { name, shader };
//# sourceMappingURL=pbrBRDFFunctions.js.map