The underlying tech behind 3D graphics rendering is constantly evolving, moving forward, whilst also delivering a better environment in which to create and realise developers artistic visions. The transition between using flat shaded geometry, to the fully programmable pixel and vertex shaded visuals of today, whilst expanding the feature-set to include texture mapping, gouraud shading, and more, illustrates this point nicely.
Tessellation then, is the next step forward. And this was exactly what NVIDIA showcased at a recent event, demoing their next flagship GPU, the GTX580, with some seriously impressive results.
Initially the presentation focuses on the benefits of tessellation when rendering a single character, showing off how a combination of the aforementioned technique, plus use of multiple displacement maps come together to create a lavishly intricate model with many layers of detail. However, the real deal demonstration comes later on, with the appearance of a fully tessellated sci-fi cityscape, pushing what is said to be close to a whopping 2 billion polygons per-second, with geometry being dynamically generated as objects get closer to the camera.
Everything is done procedurally, blending layers of tessellated geometry from one large, massively detail source mesh according to distance away from the screen. Final models for the entire scene are being generated on the fly, whereby huge levels of polygon detail replace heavy use of normal mapping. Seeing the actual geometric mesh in the video shows what looks like solid, flat shaded geometry. But look closely and you can see that we are simply seeing billions of polygons on screen at once, in wireframe mode no less.
For those who aren’t already aware, tessellation is currently being used in a small handful of console titles today. However, for the next generation it is likely to be a standard feature. Seeing as current GPU’s are increasingly no longer being held back by how many polygons they can push, then it makes sense to use more geometry, textures and shading, than resorting to large amounts of normal mapping in place of per-polygon detail.
And if this NVIDIA demo is anything to go by, then the tech in its currently advanced form is certainly going to impress as things progress.