Colin McRae Dirt 2: Engine
Codemasters delayed the PC version of Colin McRae: Dirt 2 in order to upgrade the Ego Engine of the racing game with DirectX 11 support. The cross platform architecture is capable of all modern rendering tricks but some are only used with DX11. The current API offers Hardware Tessellation which is used for a more detailed audience, tessellated cloth (banners and flags) as well as a more realistic visualization of water with more waves and splashes. Due to the Full Floating Point HDR Illumination (FP16) and High Definition Ambient Occlusion calculated via DirectCompute, Post Effects like Motion blur and filtered Soft Shadows especially the light and shadow effects of Colin McRae: dirt 2 are very realistic. Furthermore Dirt 2 receives a benefit from multi-core CPUs because of the multithreading feature of DirectX 11.
Colin McRae Dirt 2: DirectX 9 vs. DirectX 11
In a direct comparison the differences on the audience only become noticeable if you get close and pay attention - some more polygons in the right place make the figures look a little better. The flying flags are "nice to have” while the improved water visualization is really good: The car really ploughs through the water and builds up a little bow wave - additional particles on splashes make the whole scene more realistic. But the biggest difference between DirectX 9 and DirectX 11 is the illumination. Due to HDAO and nice Post Effects the visual appearance of Dirt 2 with DirectX 11 is less "overbright” and smoother. The more realistic look of the DirectX 11 version might convince some players, since there have already been mods for Race Driver Grid that were reducing exactly those warm colors and thus created a more real appearance.
We are currently working on benchmarks to demonstrate the difference in performance between DirectX 9 and DirectX 11.