static void GetRoughnessAndAngle(int roughnessIndex, int thetaIndex, int tableResolution, LTCTableParametrization parametrization, out float alpha, out float cosTheta)
{
float perceptualRoughness = (float)roughnessIndex / (tableResolution - 1);
alpha = Mathf.Max(k_MinRoughness, perceptualRoughness * perceptualRoughness);
if (parametrization == LTCTableParametrization.CosTheta)
{
// Parameterised by sqrt(1 - cos(theta))
float x = (float)thetaIndex / (tableResolution - 1);
cosTheta = 1.0f - x * x;
// Clamp to cos(1.57)
cosTheta = Mathf.Max(3.7540224885647058065387021283285e-4f, cosTheta);
}
else
{
float theta = Mathf.Min(1.57f, thetaIndex / (float)(tableResolution - 1) * 1.57079f);
cosTheta = Mathf.Cos(theta);
}
}