I'm trying to use pre-integrated sss with SH as mention in the RAD 2013 course note, and I have some question.
1. One need to convolute D(theta,r) with Y(l,0), why is theta in the range of [0, Pi/2]? For clamped cos, only the upper hemisphere matters, but for skin scattering function, shouldn't it be [0, Pi]?
2. I have compute three 1D texture, parameterized by curvature, using R8G8B8 format, and the color of the l=3 texture looks too blue.
I have the same problem with directional light texture as well, especially in the bright side of the small radius(big curvature) region. But after some curve adjustment in photoshop, the blue vanish and look exactly like the one in the Penner and Borshukov PPT.
Any suggestion? Thank you.