VISTA's visualization toolkit
provides a quasi-standard interface to
ray-tracing packages using the Neutral File Format
(NFF). Several geometrical primitives are defined by the NFF, but
only the so-called ``patch surface'' primitive is required.
Although ray-tracing quasi three-dimensional surfaces may
appear slightly unscientific at the first glance, the
specular surface model often unveils details (e.g., curvature, noise, or
very small gradients) that can hardly be discovered with
``conventional'' shading techniques.
The method has also the potential of simply
overlaying additional information using
texture and optical parameters.