Of particular importance for the exploration and understanding of the data are sub-second display rates and instantaneous visual feedback during the change of rendering parameters. To create the illusion of smooth dynamics, the image must be updated at true real-time rates. We aim at achieving projection rates of 30 frames per second. The overall latency of the system should be no more than one frame time. The design should be modular, and the performance should ideally scale almost linearly in the number of modules.
Special care has to be taken to avoid image artifacts such as spatial or temporal aliasing.
The algorithm and hardware should be flexible enough to allow for the interactive change of parameters such as shading, data segmentation, and projection modes. Current general-purpose systems fall short of achieving these goals. The high computational requirements of traditional computer graphics led to the development of special-purpose graphics engines, primarily for polygon rendering. Similarly, the special needs of volume rendering, where an image must be computed rapidly and repeatedly from a volume dataset, lends itself to the development of special-purpose volume rendering architectures. This may lead to the direct integration of volume visualization hardware with real-time acquisition devices, in much the same way as fast signal processing hardware became part of today's scanning devices.