Larry D. Seiler

The VolumePro real-time ray-casting system

This paper describes VolumePro, the world’s first single-chip realtime volume rendering system for consumer PCs. VolumePro implements ray-casting with parallel slice-by-slice processing. Our discussion of the architecture focuses mainly on the rendering pipeline and the memory organization. VolumePro has hardware for gradient estimation, classification, and per-sample Phong illumination. The system does not perform any pre-processing and makes parameter adjustments and changes to the volume data immediately visible. We describe several advanced features of VolumePro, such as gradient magnitude modulation of opacity and illumination, supersampling, cropping and cut planes. The system renders 500 million interpolated, Phong illuminated, composited samples per second. This is sufficient to render volumes with up to 16 million voxels (e.g., 256) at 30 frames per second. CR Categories: B.4.2 [Hardware]: Input/Output and Data Communications—Input/Output DevicesImage display; C.3 [Computer Systems Organization]: Special-Purpose and ApplicationBased Systems—Real-time and embedded systems; I.3.1 [Computer Graphics]: Hardware Architecture—Graphics processor;

Implementing Neon: a 256-bit graphics accelerator

High-performance 3D graphics accelerators traditionally require multiple chips on multiple boards. In contrast, Neon-a single chip-performs like a multichip design, accelerating openGL 3D rendering and X11 and windows/NT 2D rendering.

When will ray-tracing replace rasterization?

Ray-tracing produces images of stunning quality but is difficult to make interactive. Rasterization is fast but making realistic images with it requires splicing many different algorithms together. Both GPU and CPU hardware grow faster each year. Increased GPU performance facilitates new techniques for interactive realism, including high polygon counts, multipass rendering, and texture-intensive techniques such as bumpmapping and shadows. On the other hand, increased CPU performance and dedicated ray-tracing hardware push the potential framerate of ray-tracing ever higher.