// Trowbridge-Reitz distribution to Mip level, following the logic of http://casual-effects.blogspot.ca/2011/08/plausible-environment-lighting-in-two.html
float getSpecularMIPLevel( const in float roughness, const in int maxMIPLevel ) {
vec3 getLightProbeIndirectRadiance( /*const in SpecularLightProbe specularLightProbe,*/ const in vec3 viewDir, const in vec3 normal, const in float blinnShininessExponent, const in int maxMIPLevel ) {
vec3 getLightProbeIndirectRadiance( /*const in SpecularLightProbe specularLightProbe,*/ const in vec3 viewDir, const in vec3 normal, const in float roughness, const in int maxMIPLevel ) {