infiniteFX Pixel Processor - The next phase is clipping, in this phase the GPU will cut off trangles that will not be displayed on the screen. Also, to the eye invisible backsides from triangles will be removed (Triangle culling). This phase is called the Triangle setup phase in which all triangles will be calculated towards a set pixels that can be processed pixel-by-pixel. Normally in this phase the Pixels flow thru a standard pixel-rendering engine with a solid number of effects like bump-mapping and texturing. All standard rendering effect that are integrated into DirectX7 are integrated into the GeForce3 to remains compatible. However, at this certain point the game-developer has a second option ! Look at the diagram again, you'll notice nfiniteFX Pixel Processor. Yes, once again the programmer has the option to to include his/her own effects in this rendering phase on those teeny weenie Pixels.

What is a Pixel Shader - A Pixel Shader is a graphics function that calculates effects on a per-pixel basis. Depending on resolution, in excess of 2 million pixels may need to be rendered, lit, shaded, and colored for each frame, at 60 frames per second. That in turn creates a tremendous computational load. The GeForce3 can easily process this load through Pixel Shaders, and bring movie-style effects to your PC. This is an unprecedented level of hardware control for consumers. Per-pixel shading brings out an extraordinary level of surface detail—allowing you to see effects beyond the triangle level. Programmable Pixel Shaders then give artists and developers the ability to create per-pixel effects that mirror their creative vision. Rather than simply choosing from a preset palette of effects, developers can create their own. Thus, programmable Pixel Shaders provide developers with unprecedented control for determining the lighting, shading, and color of each individual pixel, allowing them to create a myriad of unique surface effects. Programmability also gives developers flexibility to create their own methods for shading objects. In addition to material effects, the NVIDIA nfiniteFX engine achieves excellent performance and enables previously impossible pixel-level effects on consumer-level platforms, because of its ability to handle four textures in a single pass. Applying multiple textures in one pass almost always yields better performance than performing multiple passes. Multiple passes translate into multiple geometry transformations and multiple Z-buffer calculations, slowing the overall rendering process.

Examples:
The figure on the left shows one of the more sophisticated techniques possible. The object is an animated, bumpy, reflective surface—something impossible to achieve in real time with previous 3D hardware. Using programmable Pixel Shaders, it's now possible to implement shiny bump maps that look correct from all angles and do not distort as the angle of lighting varies.
 

NVIDIA -Vertex and Pixel Shaders Combine to Create Exceptional Graphics
The addition of programmable Vertex Shaders and Pixel Shaders to consumer graphics processors shakes up the PC graphics market—visual quality takes a quantum leap forward. The NVIDIA nfiniteFX engine delivers a fully programmable vertex and pixel shading solution for real time 3D graphics. With the introduction of programmable Vertex and Pixel Shaders, real-time 3D graphics content takes a major step towards cinematic realism, by offering content developers the ability to create their own special effects, to define new realities, and to push the boundaries of image quality. Game players and other application users can enjoy stunning visual effects that were previously limited to pre-rendered video clips or movie screens, further blurring the line between the linear world of the movie, and the dynamic and interactive world of the 3D multimedia experience. Graphics and gaming will never be the same.