NVIDIA GeForce 256 Part 1: To buy or not to buyby Anand Lal Shimpi on October 11, 1999 5:07 PM EST
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Cube Environment Mapping
Supported by DirectX 7 and OpenGL is yet another catchphrase feature of the GeForce 256: Cube Environment Mapping (CEM). Once again, there is no arguing that CEM is a move in the positive direction for the industry, but the GeForce isn't going to be the definitive solution with CEM support.
CEM essentially uses the six faces of a cube to project an environment map onto an object. By using these six faces you retain very little warping in the environment map and obtain a very accurate projection.
Currently, no games use CEM and for this product cycle (6 months), don't expect anything to be designed with it in mind. Once the next graphics product cycle comes around, you can expect some games to be designed with CEM in mind, but as a consumer buying a GeForce 256 today, you're not getting any more than the ability to look at a few cool demos with CEM support.
There is quite a bit that goes into CEM and the possibilities are endless as to what you can do with CEM. It allows for more accurate lighting and reflection effects in certain areas and is definitely, as we mentioned before, a step forward. Unfortunately the penalty for using CEM is quite large and requires a high fill rate, much greater than what the 480M Pixels/s of the GeForce 256 is capable of delivering.
Just one of many
possibilities for CEM according to NVIDIA
Like hardware T&L, CEM is a good feature that the GeForce 256 supports, it won't be until the next product after the GeForce 256 (in about 6 months) that we'll see games beginning to use it more closely to its true potential.
What this is all beginning to sound like is the TNT versus Voodoo2 fiasco of not too long ago. If you remember, NVIDIA's Riva TNT supported 32-bit color rendering and AGP texturing before either of those two features was even remotely used in games. While AGP texturing may still not be a widely used feature, it was definitely supported by the TNT. NVIDIA rode on these two features for quite some time, banking on the fact that although the current crop of games didn't gain anything from 32-bit color rendering or AGP texturing, the potential was there.
This is very much like the current status of Hardware T&L and Cube Environment Mapping, both of which are not widely implemented features now, but they will be later on. This brings up the argument of whether or not you're going to be buying for the present or for the future games which we'll discuss in the conclusion.