3D Chips and Cards

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Multi-Texturing Or Multi-Pixel-Rendering

The equipment of 3D-chips with two parallel rendering pipelines has latest by now become a standard in the 3D-performance arena. Last year this was implemented into the Voodoo2 chip set for the first time. In the past a pixel had to be rendered in two or more passes to reach higher realism, as e.g. for the lighting effects in Quake, Quake2, Unreal, Halflife or Shogo. The rendering of the texture and the lighting map can be done in parallel and thus at double the speed if the 3D-chip has got two parallel rendering pipelines. If a game is less complex and requires only one rendering pass, each of those pipelines can render a different pixel, thus doubling the fill rate (this is something that Voodoo2 could not do). All new or upcoming 3D-chips have at least two rendering pipelines. The future 3D-chips will soon come with four or more pipelines whilst at the same time 3D-games will require more than only two rendering passes for each pixel.

We are moving quickly towards a more and more realistic 3D-gaming experience, so that the textures need to be a lot more detailed than they used to. The Voodoo3 only supports textures up to 256x256, whilst the rest of the new 3D-chips can handle 2048x2048. This offers a higher level of detail in 3D-scenes. Other chips have problems with non-square textures, which also reduces realism. Today you should expect the support of 2048x2048 textures, it will be more pretty soon.

Bump mapping is one of those 'hip' 3D-features to talk about. A lot of blah-blah was going on about it in the last twelve months and many people were trying to make a big deal about it on the Web although no game did really support it. Today bump mapping is implemented into DirectX and game developers are starting to play with this feature. It enables you to see a realistically shaped surface with a relief on it, rather than the boring good old flat 3D-surfaces we know so well from Quake2 or many other games. A good example is waves on a water surface. Environment mapping can increase the realism even further by adding realistic reflections to those surfaces. Most 3D-chips are currently realizing bump mapping by adding another alpha-blending rendering pass to the rendering process, which gives an 'OK' kind of impression in many cases, but it's still not really realistic. Matrox' G400 and supposedly 3Dlabs' Permedia3 are the only two chips that do real hardware bump mapping with environment maps right now, which is looking way better than the pseudo-bump mapping of its competitors. As soon as game developers make heavy usage of this nice feature, the other 3D-chip makers will have to come up with their hardware bump mapping solution as well.