Popular console offroad racing game “Colin McRae: Dirt 2” is coming to PC’s soon, and the developer behind it just released a PC Demo. Fully supporting both DirectX9 (for those XP users) and DirectX11 (for bleeding-edge Windows7 users), Bit-Tech tries it on both to see just what changes in DirectX11 and if it really makes any big impact.
In Dirt 2, it’s used in three situations: when your car crosses a pool of water, for the crowds watching the races and for flags flying by the side of the track. As you can see from these pictures, tessellation helps add more realistic, more detailed shapes where you would like it, but wouldn’t want to use computationally intensive high-detail models.
According to AMD: “The CPU generates the height field texture when cars drive through it. The tessellator generates hundreds of triangles based on the camera position. The result: A beautiful, physically accurate, dynamic water surface. In the DirectX 9 version of the game, the surface is an illusion represented by just two triangles.”
As well as creating extra ripples in the water, it's also used for adding more kinks and ripples in flags that are fluttering in the wind. Tessellation is also useful for creating realistic looking curves, and it's this application of the technique which is used to make the low polygon crowd models more detailed.
So of course, the visuals are better. Gameplay doesn’t change, thankfully, but the differences are so little.. Well, here’s what they say:
The difference between DirectX 9 and DirectX 11 is clear, and it doesn’t make for good reading for the new API. The average score in DirectX 11 is 30% slower than in DirectX 9. The story of minimum frame rates is even harder to ignore – in DirectX 9, the game is nearly 40% faster.
and
We were expecting the lovely rippling effects in the flags to vanish without tessellation to smooth out their supple curves. However, all of the flags in the demo rippled just as convincingly in DirectX 9 mode as they did in DirectX 11 mode. Likewise, all of the textures looked the same too. You’d need a seriously keen eye and brown paper envelope full of cash from one of the creators of Dirt 2 to notice any real difference between textures in the two versions of DirectX.
And much more. Now, this is a pre-release Demo version of the game, so things might change in the final product. For an early impression tho, it doesn’t sounds like there’s much need in rushing out to get a DirectX11 system. Makes you wonder if perhaps NVidia was onto something with their “DirectX11 won’t increase sales” comment a while back.
via bit-tech.net | Feature – DirectX 11 performance first look: Dirt 2.
