Carmack Looks To 64-Bit Future

John Carmack, the programming powerhouse behind Quake III: Arena, wrote up a .plan missive this weekend outlining how his vision for 3D graphics progress extends much beyond the current 32-bit color standard. With the unveiling at WinHEC of Nvidia's and ATI's next generation of 3D hardware, some may be wondering why any game could need so much raw power. Carmack explains that a standard for 64-bit color is necessary because faster 3D cards aren't just being used to push higher resolution images (more pixels) but also to do more with each pixel.

New complex environmental effects, such as the bump and environmental mapping, which better represent the textures and reflections in real-world materials, take many layers of data and combine them at the pixel level. Per pixel shader effects were first introduced in Quake III, and advanced general shader support is a central feature of the GeForce 2 GTS. The problem with current 32-bit lies in making several sequential calculations of, say, multiple dynamic light sources. At each step, complex calculations must be rounded to fit into the 32-bit standard built into current hardware. Since rounding introduces imprecision at each step, several iterations of this can make for dithering and obvious color banding even with 32-bit color.

Carmack also outlined recent discoveries that should close the gap between the real-time graphics rendering found in games and Pixar-like pregenerated movie rendering. With the high end of the 3D hardware market advancing so quickly up the gigapixel performance scale, it's time for developers to take a hard look at how real games can best use this power. Carmack enjoys particular influence in 3D development, so you can expect his suggestions to be considered by hardware vendors. However, any eventual transition to a new color format won't make it into shipping products for many product cycles, since even 32-bit color itself only became the reigning standard last year.