1. A method for visualizing a portion of a region of obstruction created by an ellipsoidal solid, comprising: applying, in a processor, a scaling transformation to elements of a data set defining a viewing location and the ellipsoidal solid to determine a cone region; computing, in the processor, a ray intersection interval with the cone region; determining, in the processor, whether the ray intersection interval intersects with the cone region; discarding, in the processor, pixels of the ray intersection interval that do not intersect with the cone region; applying, in the processor, appropriate shading and depth values to pixels of the ray intersection interval that do intersect with the cone region; and displaying the pixels having shading and depth values.