Interactive visualization of large scalar voxel fields

A technique is given allowing interactive visualization of large, scalar, discrete volume fields as semitransparent clouds `on the fly´, i.e. without preprocessing. Interactivity is not restricted to geometric transformations, but includes all possible methods of processing the data. The system flexibly trades-off quality for performance at any desirable level. In particular, by using a scanline based method and a DDA-based traversing scheme instead of ray-tracing one achieves real-time processing during previewing. By means of the `pyramidal volume´ traversing technique, one achieves high-quality, constant-time filtering, independent of the data resolution. Several filters help to detect `fuzzy´, obscured hot spots, even within noisy data. The visualization pipeline allows the application of filters at four different stages, maximizing their flexibility. Four different illumination models have been implemented