[tuhopuu-devel] Re: Minnaert diffuse shader

[Jonathan Merritt]

Jonathan Merritt wrote:

> To implement this "Blender" version, I would propose a straightforward 
> modification of the current nVIDIA model (refer to 
> source/blender/render/intern/source/rendercore.c):
>    i = nl * pow( nl, 1-k ) * pow( (1.001-nv), k )
> o  "darkening" = k, and is in the range [0,1]
> o  increasing k increases the limb darkening effect.
> o  (NB: I'm not sure 100% how Alfredo's energy conservation term fits 
> into all of this yet.)


Actually, it's simpler to modify the "original" version:
    i = nl * pow(MAX2(nv * nl, 0.001), k)

This also obviously yields the result that when k = 0:
    i = nl
which is the Lambertian result.

Sorry about that...

Jonathan Merritt.