Gridigrator:A Very Fast Volume Rendererfor 3D Scalar Fields Defined on Curvilinear Grids

A. Globus, Technical Report RNR-92-001


Gridigrator is a software module which renders scalar volumes on curvilinear grids by casting rays along grid lines. Each ray deposits a scalar result on a vertex of the grid's face. This scalar is the result of a `deposition' function applied to the data points the ray intersects. The resulting scalar field on a surface embedded in three dimensions may be visualized using standard techniques. This variation on ray casting scalar field volume rendering is very fast and can be trivially combined with polygon, line and point based visualizations to create images. Gridigration is a O(n) technique where n is the number of grid nodes. Gridigrator is much faster than traditional ray casting volume rendering on identical workstation hardware. Gridigrator on a workstation is somewhat faster than traditional ray casting volume rendering on a massively parallel supercomputer. Although interpretation of results can be difficult, we expect gridigration to be useful for quick look surveys of scalar fields to find features of interest. A generalization of gridigration based on a medical x-ray imaging analogy is briefly discussed as a promising avenue for further research.

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