Carmack talks about GeForce3

John Carmack, the well-known programmer responsible for the Doom and Quake game engines, has posted a lengthy .plan update on the just-announced GeForce3. The posting comes shortly after Carmack demonstrated an early version of Doom III as part of the GeForce3 announcement at the Macworld Expo in Tokyo. His concise opinions on the new Nvidia design are that it's "fantastic" and "I haven't had such an impression of raising the performance bar since the Voodoo 2 came out, and there are a ton of new features for programmers to play with."

He goes into detail about how the GeForce3's major new features, pixel and vertex shaders, make a technical difference in 3D programming. He's most excited about how much easier it is to do complex texture effects and animation blending with vertex shaders, which are little programs that the graphics card runs to make transform and lighting operations dynamic and customizable. Carmack noted that the GeForce3's vertex shaders allow for things that just couldn't be accomplished with graphics hardware before, and that the tools themselves are easy to deal with, saying, "The vertex program instructions are what SSE should have been." (SSE is the multimedia instruction set Intel introduced with the Pentium III.)

However, Carmack isn't as positive on the way pixel shaders have been worked out in the GeForce3 and DirectX 8. He's quick to say that "the way the pixel shader functionality turned out is painfully limited, and not what it should have been." Specifically, this part of the GeForce3 would seem to have been designed to be more general and customizable, a lot like the vertex shaders turned out. But, apparently, the GeForce3 is capable of a relatively limited number of effects based on environmental bump mapping, which is used to give objects the appearance of a surface with a highly varied texture.

The GeForce3 has been initially announced as a $600 option for new Mac desktops and will be available in late March. Pricing and availability of a PC version have not been officially released.