Interview with Croteam's Dean Sekulic @ Beyond3D

We understand SS2 is using a brand-new visible surface determination algorithm and you mention using the hardware supported "occlusion query". With recent hardware coming out with ever more pixel culling support, do you think the industry is on the right path, does it needs to devote more effort towards eliminating pixels that aren't visible before going into the shader pipelines, or even should it seek a radical alternative to this problem?

To be quite honest, I haven't thought yet of radical alternative. So far - so good. I mean, early-Z rejection can really do wonders. For example, we are sorting our opaque objects from front to back (one more reason why geometry instancing is not-that-good, by the way!). This way, early per-pixel rejections tends to eliminate lots occluded pixels, and if we reverse the sort order, drop in frame rate will be considerable (something like 30-40%). I guess, this counts as an evidence that we do need optimizations like that in GPUs.