Variable getPBRDirectSheenConst
getPBRDirectSheen: "\nfn BRDF_Sheen(\n lightDirection: vec3f,\n viewDirection: vec3f,\n normal: vec3f,\n sheenColor: vec3f,\n sheenRoughness: f32\n) -> vec3f {\n let halfDir: vec3f = normalize( lightDirection + viewDirection );\n\n let dotNL: f32 = saturate( dot( normal, lightDirection ) );\n let dotNV: f32 = saturate( dot( normal, viewDirection ) );\n let dotNH: f32 = saturate( dot( normal, halfDir ) );\n\n let D: f32 = D_Charlie( sheenRoughness, dotNH );\n let V: f32 = V_Neubelt( dotNV, dotNL );\n\n return sheenColor * ( D * V );\n}\n" = ...
WGSL functions to calculate sheen BRDF specular direct contribution.