Ray Tracing

Goddamn all of these homework threads. Let's talk about something interesting.

I'm starting work on a ray-tracer for shits, /proggles/ Any tips on speed improvements? It's being written in C.
I know the show stopper (usually) is having to check each element in the scene and see if it has been intersected by a casted ray. Any ideas on improvements in that area?

>>43
You're one of those fuckers in 212.  There's one section of that.  All I have to do is go into the class tomorrow, discreetly look at everyone's browsing history, and find the sap who has /prog/.  And incognito mode or equivalents won't work.  I'm a fucking ninja.  Don't [spoiler]turn[/around] around