It seems like it would be likely for some geometry to entirely occlude other geometry in a scene. Are they any sort of early out methods of not wasting time on geometry that is covered, besides just checking each point in the depth buffer? I guess one way might be to filter out such geometry before rasterization, but I'm curious to know what other techniques are used.
Does opaque mean "non-transparent" here?
@pickle-eye Absolutely! Reducing the number of triangles to rasterize is a good way to speed up frame rates. For one, we can cull triangles outside of the view frustum, or cull triangles facing away from the camera (see backface culling). More generally, we want to avoid processing any triangles hidden from our camera (e.g., behind other triangles). When rasterizing indoor environments that are divided into a bunch of individual rooms, one can use portal culling to quickly remove geometry associated with rooms completely hidden from our camera. If you're interested in learning more, check out this article from GPU Gems.
@bunbohue Yes, "opaque" means that an object is not transparent.