RE: [Algorithms] Doom lightmaps

[Brian H. <bw...@wk...>]

At 09:32 AM 2/26/01 +0000, you wrote:
>* Burn fill rate

Yes.

>* Stencil methods in particular have very variable fill rate cost

Definitely.

>* Require skinning to be done CPU side (so you can calculate the silhouette)

Yep.

>* Require fancy silhouette extraction algorithms (brute force extraction =
>expensive)

I wouldn't say something _fancy_ is required, but this is definitely a 
costly operation.

>* They only really work for dynamic lights and typically you can only
>have a few on screen before your frame rate suffers very badly.

Eh?  You can do static lights quite well too, e.g. shadow volume BSPs.

>* Force the artists to cap objects

I have not found this to be the case.

>* Make it essential for all meshes to be manifold

Nor this.

>* May make lit semi-transparent materials a total nightmare

Can be approximated with projected lights.

>* Require the artists to be very careful when modelling to avoid
>unfortunate self shadowing.

?

>* Require that the artists and designers don't try to use too many
>polys. You can forget about having 100k triangle / frame scenes with
>full on volumetric shadows

At this point I strongly believe that high polygon counts can be safely 
eschewed for better and more accurate lighting.  We're at the point of 
significantly diminished returns for cranking up polygon counts (especially 
with bump mapping available now), so exchanging triangle density for more 
complex lighting is definitely worth while.

Brian