I learned it from a paper "Spherical Harmonic Lighting: The Gritty Details" (link below), where the author uses a different form of the equation. I like the 3D

I learned it from a paper "Spherical Harmonic Lighting: The Gritty Details" (link below), where the author uses a different form of the equation. I like the 3D in this one. http://silviojemma.com/public/papers/lighting/spherical-harmonic-lighting.pdf http://silviojemma.com/public/papers/lighting/spherical-harm...