Game Development Stack Exchange is a question and answer site for professional and independent game developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'd like to know how many shadow casting lights are supported in modern games, such as Uncharted 2, Crysis 2, Modern Warfare 2, Halo: Reach, etc. Do they all limit themselves to just a couple of shadow casting lights, or do the numbers vary wildly?

share|improve this question
up vote 6 down vote accepted

I haven't played MW2 and Halo, but Crysis 2 and Uncharted 2 don't have lots of dynamic shadow-casting lights at the same time. I can remember mostly 2 shadow casters at the same time; naturally they wanted to keep shadow resolve quick. Generally shadows are expensive to compute, so most games will have 2-4 shadow-casting lights with several non-shadow-casting lights nearby, then shadow resolve will switch between them depending on light’s screen presence. Two shadow casters are enough for a nice visual, especially when you're targeting consoles with limited resources and have to do other lighting parts quick and beautiful, which means lots of pre-computed stuff.

I'm sure there are papers on Crysis 2 and Uncharted 2 lighting somewhere, but here is a pretty generic guess mentioning most modern techniques: detailed character shading via lighting baked into AO and diffuse maps, cascade shadows for global light source and several dynamic lights per pass via some spatial screen partitioning and a normal buffer, with the rest of the lighting baked into vertexes through some form of PRT.

That's not a very useful info for your game, you know. Number of shadow-casting lights depends on the approach to lighting, which in turn depends on lots of things like a renderer's architecture, expected scene complexity, chosen shadow maps for a global light, desired post-effects and overall "heaviness" of the shaders.

Also keep in mind that dynamic lights, shadow-casting or not, aren't the biggest part of overall lighting scheme, there are other important points to consider like character lighting/shading, opaque/alpha blend geometry and various post-processing effects.

share|improve this answer
I've found that any more than two active light sources casting shadows just makes for a big visual mess and even two lights gets confusing if they both have the same hue/value slapped onto the ground (you just don't see that kind of equal intensity lighting very often in real life). – Patrick Hughes Aug 30 '11 at 20:51

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.