Hello Jake
> The reason I'm emailing you is I'm very curious as to how you've done 
> the light rays in your Final Audition demo - in that scene with the 
> spherical harmonics/bump mapping.
>
> Does it have to do with the shadowmap?
The effect is simple but very fillrate hungry.
You draw triangles (30 will be ok) parallel to the camera and use a 
shadowmap
to compute transparency. Moreover you use a KILL pixel command
in a shader to speed things up a little by saving some of the bandwidth.
 
And that's all :).
It's not an intelligent approach but very simple to write.
 
 
Cheers!
 
Michal

-------------------------

Hello Jake,
> Thanks for the speedy reply!!
>
> However, I still don't quite understand..
>
> are the triangles covering the whole screen? if not, where do they 
> start/end?
>
> How do you get the correct shadow map u/v coordinates?
>
> Why so many triangles?
Actually maybe It is a little confusing.
Basically you draw cone from a source of
the light. The cone is made of parallel triangles
(a technique similar to display volumetric data).
There must be 30 triangles to achieve good density.
The u/v's are projected like on normal surfaces.
Today I think I would write it in other way, but
I would need to take a look into some volume rendering
books first.
 
Cheers!
 
bonzaj