/**
 *
 * Original approximation by Christophe Schlick '94
 * NOTE: prefer to use {@link fresnel_Schlick_optimized} instead, this primarily exists for reference purposes
 * @param dotVH
 * @return {number}
 */
function fresnel_Schlick_original(dotVH) {
    return Math.pow(1.0 - dotVH, 5.0)
}