Geometry Processing & Tessellation

One of the slides makes a very important observation that over the past five generations of GeForce GPUs since the GeForce FX 5800, geometry processing ability of GPUs, and the geometric complexity of games have seen stunted development when compared to shader performance and implementation. While the performance and complexity of the shader domain grew by over 150 times between these generations, that of geometry pretty much took the back seat with less than 3 times increment in geometry performance. This is what has come in the way of games being as photo-realistic as movies with 3D graphics, where the producers splurge on rendering farms that take care of high geometric complexity.



Tesselation is the way forward for geometric complexity to keep up with today's 3D graphics. The more complex the geometry of a 3D object is, the more accurately its shape is drawn on the screen. Tessellation allows the GPU to focus its resources on select portions of the 3D object where more complexity is required as instructed by a displacement map, and add to its geometric detail. DirectX 11 allows the GPU to create generalized geometry.



The following slides describe the way tessellation works in DirectX 11, and a few demos.