The design principles of a hardware acceleratorfor volume rendering are described. The architecture represents a voxel subsystem which interfaces easily to any existing workstation. Host requirements are low since it contains a multiport memory holding the complete data set and all arithmetic units needed to perform an effective visualization.

Our approach aims at virtual reality by providing some “real‐world” examination techniques. The user (e.g., a physician) is enabled to analyze the data set from an arbitrary viewpoint and, even more, to “walk through” the volume model. For a realistic impression, the machine produces perspective projections, supports the illumination by non‐parallel light comingfrom a freely movable point light source and provides depth cueing. The objects are Phong shaded at a rate of 10⁷ operations/s and can be displayed semitransparently. One unit achieves interactive speed: for real‐time operation only a small number of units (typically 4‐16) must be placed in parallel.