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

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// Do not edit.
import { ShaderStore } from "../../Engines/shaderStore.js";
const name = "openpbrVolumeFunctions";
const shader = `struct OpenPBRHomogeneousVolume {vec3 extinction_coeff; 
vec3 ss_albedo; 
vec3 multi_scatter_color; 
vec3 absorption_coeff; 
vec3 scatter_coeff; 
float anisotropy; };OpenPBRHomogeneousVolume computeOpenPBRTransmissionVolume(
in vec3 transmission_color,
in float transmission_depth,
in vec3 transmission_scatter,
in float anisotropy
)
{OpenPBRHomogeneousVolume volumeParams;volumeParams.absorption_coeff=vec3(0.0);volumeParams.scatter_coeff=vec3(0.0);volumeParams.anisotropy=anisotropy;
#ifdef GEOMETRY_THIN_WALLED
volumeParams.scatter_coeff=vec3(1.0);volumeParams.anisotropy=1.0; 
volumeParams.extinction_coeff=volumeParams.absorption_coeff+volumeParams.scatter_coeff;volumeParams.ss_albedo=vec3(1.0);
#else
if (transmission_depth>0.0) {vec3 invDepth=vec3(1./maxEps(transmission_depth));volumeParams.extinction_coeff=-log(maxEps(transmission_color.rgb))*invDepth;volumeParams.scatter_coeff=transmission_scatter.rgb*invDepth;volumeParams.absorption_coeff=volumeParams.extinction_coeff-volumeParams.scatter_coeff.rgb;float minCoeff=min3(volumeParams.absorption_coeff);if (minCoeff<0.0) {volumeParams.absorption_coeff-=vec3(minCoeff);}
volumeParams.extinction_coeff=volumeParams.absorption_coeff+volumeParams.scatter_coeff;volumeParams.ss_albedo=volumeParams.scatter_coeff/(volumeParams.extinction_coeff);} else {volumeParams.extinction_coeff=volumeParams.absorption_coeff+volumeParams.scatter_coeff;volumeParams.ss_albedo=vec3(0.0);}
#endif
return volumeParams;}
OpenPBRHomogeneousVolume computeOpenPBRSubsurfaceVolume(
in vec3 subsurface_color,
in float subsurface_radius,
in vec3 subsurface_radius_scale,
in float anisotropy
)
{OpenPBRHomogeneousVolume volumeParams;volumeParams.absorption_coeff=vec3(0.0);volumeParams.scatter_coeff=vec3(0.0);volumeParams.anisotropy=anisotropy;volumeParams.multi_scatter_color=subsurface_color;vec3 mfp=subsurface_radius_scale*vec3(subsurface_radius);volumeParams.extinction_coeff=vec3(1.0)/maxEps(mfp);volumeParams.ss_albedo=multiScatterToSingleScatterAlbedo(subsurface_color,anisotropy);volumeParams.scatter_coeff=volumeParams.ss_albedo*volumeParams.extinction_coeff;volumeParams.absorption_coeff=volumeParams.extinction_coeff-volumeParams.scatter_coeff.rgb;float minCoeff=min3(volumeParams.absorption_coeff);if (minCoeff<0.0) {volumeParams.absorption_coeff-=vec3(minCoeff);}
volumeParams.extinction_coeff=volumeParams.absorption_coeff+volumeParams.scatter_coeff;return volumeParams;}
vec3 sss_pdf(float r,vec3 d)
{d=max(vec3(1e-4f),d);return (exp(-r/d)+exp(-r/(3.0f*d)))/max(vec3(1e-5f),8.0f*PI*d*r);}
float sss_samples_pdf(float r,float d)
{d=max(1e-4f,d);return exp(-r/(3.0f*d))/(6.0f*PI*d*r);}
float sss_samples_icdf(float x,float d)
{d=max(1e-4f,d);x=max(1e-4f,x);return -3.0f*log(x)*d;}
float samples_scale(float x,float d)
{return 1.0f-exp(-x/(3.0f*d));}
vec3 sss_get_position(sampler2D depth_texture,vec2 tex_coord,vec2 render_resolution,mat4 inv_proj)
{vec4 P=vec4(tex_coord,texelFetch(depth_texture,ivec2(tex_coord*render_resolution),0).x,1.0f);P.xy=2.0f*P.xy-1.0f;P=inv_proj*P;return P.xyz/P.w;}
float sss_filter_scale(float currZ,mat4 proj)
{return 1.0f/dot(vec2(proj[2].w,proj[3].w),vec2(currZ,1.0f));}
float projective_to_pixels(float proj_dist,mat4 proj,vec2 resolution)
{return proj_dist*proj[1][1]*resolution.y;}
float pixels_to_projective(float pixel_dist,mat4 proj,vec2 resolution)
{return pixel_dist/(proj[1][1]*resolution.y);}
vec3 sss_convolve(sampler2D sss_irradiance_texture,sampler2D depth_texture,vec2 render_resolution,vec3 d,mat4 proj,mat4 inv_proj,int sample_count,vec2 noise)
{vec2 tex_coord=gl_FragCoord.xy/render_resolution;vec3 unconvolved_irradiance=texelFetch(sss_irradiance_texture,ivec2(gl_FragCoord.xy),0).rgb;vec3 curr_pos=sss_get_position(depth_texture,tex_coord,render_resolution,inv_proj);float dmax=max3(d);float max_dmax=0.1*float(sample_count);if (dmax>max_dmax)
{d.rgb*=max_dmax/dmax;dmax=max_dmax;}
float dz=dmax*sss_filter_scale(curr_pos.z,proj);mat2 projMat2d=mat2(proj);if (determinant(projMat2d)*dz<1e-4f)
return unconvolved_irradiance;float overscan_size_in_pixels=max(render_resolution.x,render_resolution.y)*0.1;const float filter_crop_ratio=0.8f; 
float crop_radius=projective_to_pixels(sss_samples_icdf(1.0f-filter_crop_ratio,dz),proj,render_resolution);if (crop_radius>overscan_size_in_pixels)
{d.rgb*=overscan_size_in_pixels/crop_radius;dz*=overscan_size_in_pixels/crop_radius;}
float filter_samples_scale=samples_scale(pixels_to_projective(overscan_size_in_pixels,proj,render_resolution),dz);vec3 irradiance_sum=vec3(0.0f);vec3 weight_sum=vec3(0.0f);for (int i=0; i<sample_count; i++)
{vec2 r=fract(plasticSequence(uint(i+sample_count))+noise*0.2);r.x*=TWO_PI;r.y*=filter_samples_scale;float icdf=sss_samples_icdf(1.0-r.y,dz);vec2 sample_uv=tex_coord+icdf*projMat2d*vec2(cos(r.x),sin(r.x));vec4 sss_irradiance=texelFetch(sss_irradiance_texture,ivec2(sample_uv*render_resolution),0);float dist=distance(curr_pos,sss_get_position(depth_texture,sample_uv,render_resolution,inv_proj));if (dist>0.0f)
{vec3 weights=sss_irradiance.a/sss_samples_pdf(icdf,dz)*sss_pdf(dist,d.rgb);irradiance_sum+=weights*sss_irradiance.rgb;weight_sum+=weights;}}
return vec3(weight_sum.r<1e-5f ? unconvolved_irradiance.r : irradiance_sum.r/weight_sum.r,
weight_sum.g<1e-5f ? unconvolved_irradiance.g : irradiance_sum.g/weight_sum.g,
weight_sum.b<1e-5f ? unconvolved_irradiance.b : irradiance_sum.b/weight_sum.b);}`;
// Sideeffect
if (!ShaderStore.IncludesShadersStore[name]) {
    ShaderStore.IncludesShadersStore[name] = shader;
}
/** @internal */
export const openpbrVolumeFunctions = { name, shader };
//# sourceMappingURL=openpbrVolumeFunctions.js.map