message: Remove incorrect approximations
diff: @@ -775,31 +775,6 @@ static double2 __UNUSED prefilteredDFG_Karis(double NoV, double roughness) {
  return double2(-1.04, 1.04) * a004 + double2(r.z, r.w);
  }
  -static double2 __UNUSED prefilteredDFG_Cloth_Ashikhmin(double NoV, double roughness) {
  - const double4 c0(0.24, 0.93, 0.01, 0.2);
  - const double4 c1(2.0, -1.3, 0.4, 0.03);
  - double s = 1.0 - NoV;
  - double e = s - c0.y;
  - double g = c0.x * std::exp2(-(e * e) / (2.0 * c0.z)) + s * c0.w;
  - double n = roughness * c1.x + c1.y;
  - double r = std::max(1.0 - n * n, c1.z) * g;
  - return {r, r * c1.w};
  -}
  -
  -static double2 __UNUSED prefilteredDFG_Cloth_Charlie(double NoV, double roughness) {
  - const double3 c0(0.95, 1250.0, 0.0095);
  - const double4 c1(0.04, 0.2, 0.3, 0.2);
  - double a = 1.0 - NoV;
  - double b = 1.0 - roughness;
  - double n = std::pow(c1.x + a, 64.0);
  - double e = b - c0.x;
  - double g = std::exp2(-(e * e) * c0.y);
  - double f = b + c1.y;
  - double c = n * g + c1.z * (a + c1.w) * roughness + f * f * std::pow(a, 8.0);
  - double r = std::min(c, 18.0);
  - return {r, r * c0.z};
  -}
  -
  void CubemapIBL::DFG(Image& dst, bool multiscatter) {
  auto dfvFunction = multiscatter ? ::DFV_Multiscatter : ::DFV;
  JobSystem& js = CubemapUtils::getJobSystem();
  