Alex Vlachos rendering and shader developer for valve software posts and makes available a PDF file of the GDC talk he gave on Left 4 Dead 2’s challenges in rendering wounds on zombies in real time. The presentation covers a bit of the development and discovery process where multiple techniques were tested before finally finding the best solution. A little too much gore maybe for a Saturday morning, but still a good read if you have the stomach for it! Find and read the presentation here.