Anyone read Laurent Belcour's paper on layered material?

[T.C. Chang]

Laurent Belcour's recent paper on layered material looks amazing, here is the link https://belcour.github.io/blog/research/2018/05/05/brdf-realtime-layered.html. But I have got many questions regarding some formulae listed in the paper, especially equation 32 & 33. I think they are both missing the "w_i dot normal" term...? Also, equation 7 uses the FGD_infinity term instead of the previously defined FGD term. He stated that FGD_infinity is for rough interface, but isn't FGD already defined for rough interface?

[dawelter]

I read it and it is on my list to implement next. But I didn't dive into the details yet.

Regarding FDG_inf: To my understanding it is basically a better version of FDG. I think there is only one FDG table which is what is used for light transport simulation. Actually calculating FDG_inf seems to be expensive since the Author mentions stochastic evaluation. So I presume that the table is filled with FDG_inf where needed and normal FDG otherwise.

[T.C. Chang]

After thinking for a while, I think you are right. Partially filling the FGD table with FGD_inf is actually a good point, and I think the author meant that way. I am planning on implement this technique too. We can discuss about the details if there is any problem during implementation.