Students Evaluate Ray Tracing From Developers' Side

Vigile writes "Much has been said about ray tracing for gaming in recent weeks: luminaries like John Carmack, Cevat Yerli and NVIDIA's David Kirk have already placed their flags in the ground but what about developers that have actually worked on fully ray traced games? PC Perspective discusses the benefits and problems in art creation, programming and design on a ray traced game engine with a group of students working on two separate projects. These are not AAA-class titles but they do offer some great insights for anyone considering the ray tracing and rasterization debate."

Comments

Re:What's the point ...

[argent]

Realistic lighting allows you to use those clever algorithms in your head that you've learned over the past 20+ years in the real world, so when you see a flicker of a reflection or a change in the shadows in a darkened tunnel you can turn and blast the damn camper on the opposite rooftop before he nails you with his sniper rifle.

I'd quibble.

[jd]

Raytracing is superior to doing nothing, but conetracing, non-uniform conetracing and wavetracing are all superior to raytracing, and all but wavetracing benefit from adding in radiosity. The advantages of raytracing over all other methods are that it is totally parallelizable and can be implemented using a fairly simple set of algorithms, potentially allowing for a truly gigantic number of compute elements on a single die. One big headache, though, is that to get a significant visual improvement, you have to cast a large number of rays per pixel (or you can't do scatter properly) and you need multiple generations (ie: secondary light sources), where each generation needs to be processed twice - once for direct reflection, once for refraction. This would be fine, but it means different rays will take a different length of time to complete, which in turn means that to get smooth motion, you have to calculate the time for the slowest possible path and synchronize to that.

Typically, however, games manufacturers do NOT mean "raytracing" when they say "raytracing". They mean basic rendering. ie: Applying of shaders and other simple colouring techniques. Renderman, the rendering package used to produce movies like Finding Nemo, uses rendering, not raytracing. Rendering is popular with movie producers because it's fast and "good enough". (Audiences differ on the subject, with plenty of people preferring model-based special-effects because the lighting is real and the reflections are correct - well, they'd better be!) My fear is that true raytracing and physically correct lighting models will be totally overlooked in favour of things that will be cheaper to produce and therefore make more money.