You've read our in-depth interview with the designer of the game, but here's a chance to you to get a clear look at the awesome zombie slaughterfest in Left4Dead. Valve has given us four exclusive screenshots from its upcoming multiplayer shooter, along with a detailed briefing explaining the graphical enhancements they've made to the game engine since acquiring Turtle Rock Studios. The new post-processed filmic effects and advanced shadow rendering makes the game look like nothing you've seen before. It sure doesn't look like Half-Life 2!
Left4Dead Source Engine Details:
The infected hoard in Left4Dead are realistically animated so they anticipate and lean into turns based on the curvature of their AI navigation paths.
The physics are simulated with a blending of traditional animation and ragdoll physics. In addition to location-specific damage, shoves and gunshots are physics interactions, based on the location of impact and what the infected hits afterward.
Even if zombies are brain dead, the AI driving them is smart. The infected will climb and path-find over objects, not just around them. They'll even break down walls and doors to get to you.
Filmic effects: Color correction allows the developers to maintain a specific palette while controlling saturation and visual elements based on their importance to the player and the scene.
Film grain is enhanced in dark areas, and contrast is ramped up to sharpen areas with high visual detail. Subtle reduction of brightness at the top and sides of the screen draws your attention toward the action and increases the tension.
Self-shadowed Normal Mapping locally alters surface orientation to cause detailed lighting effects. This feature incorporates local self-shadowing information to add greater surface richness. Surfaces will react to lighting from radiosity as well as dynamic lights in the scene, like your flashlight (which cast dynamic soft-shadows in the level).