ray tracing without rays

Umm... yes. Raytracing means following a ray from a point and checking what it collides with. The object itself can be anything that you can come up with a formula for. Cone, torus, triangle, plane, cube, bezier patch, etc, etc, etc.

well duh.

i mean testing the visable shapes against things other than a ray. like tracing a cone to see if it collides with a box.

Well, yes, I suppose you could. However, it serves no purpose and is more complex mathematically.

serves much purpose. if a the rays fan out over a 35 degree angle, then its much faster to test a cone than all the different rays.

You mean, using a cone / object intersection test for fustrum culling? That makes a lot of sense; it''s fairly commonly done. Still, you need some per-pixel test (usually rays) to actually draw the thing.

I say "usually rays" because "raytracing" has been modified to use a volume for each pixel; replacing point samples with areas, eliminating the need for antialiasing. But I have a feeling that''s not what you were talking about.