Re: [Algorithms] Lighting (HDR)

[Fabian G. <f.g...@49...>]

> That's sort of an over simplification.  For example, The Torrance- 
> Sparrow BRDF has both 1/cos theta_i and 1/cos theta_o terms, not to  
> make the old shading models match with the new reflection equation,  
> but intuitively to account for the fact that as you approach grazing  
> angles, the total projected area of all microfacets seen along a ray  
> increases (and goes to infinity at grazing when you hit the point of  
> your ray going through all of the microfacets!) (It is also reciprocal.)

Yes, if you divide both by cos(theta_i) and cos(theta_o) it's reciprocal 
again (since it's symmetrical in both angles), but you cannot divide by 
just one of them.

-Fabian