float SphericalGaussianFresnelFunction(float LdotH,float SpecularColor)
{
  float power = ((-5.55473 * LdotH) - 6.98316) * LdotH;
  return SpecularColor + (1 - SpecularColor) * pow(2,power);
}

FresnelFunction *= SphericalGaussianFresnelFunction(LdotH, specColor);