POV-Ray© is a freeware raytracing program available for a wide range of computer platforms.
I've been using POV-Ray since v2.2 especially for rendering the structure of crystall lattices.
But it do so much more!
A raytracing program (or raytracer) is a program that renders a photorealistic image from a given
scene description. It does so by "shooting" optical rays from the virtual position of the observers
eye (or camera) into the scene, tracing eventual hits between these rays and objects in the scene.
By following simplified inverted optical laws an image of the scene is created on the screen.
Compared to early raytracing programs, POV-Ray in its recent version 3.1 has evolved a very comprehensive
macro language for the description of the scene including different kind of basic object shapes and
modifiers, calculus functions as well as descriptive elements like loops and conditionals.
A sample scene of my macro 'geodesic.inc'. All the shapes seen in this image are created on the basis of geodesical spheres, i.e. spherical shapes with a triangular structured surface.
Simple triangular geometry done by POV-Ray. With some little
help of functions defined in my second macro package 'geometry.inc'.
A cyan colored triangle is shown with its inner circle (yellow), outer circle (magenta) and their
respective center points. Also implemented is the center of mass and the surface normal (blue)
of the triangle.
Essentially the same geometry as in the previous picture but extruded into the third dimension.
I just encountered a - as it seems - quite common problem with surface-of-revolution SOR objects in POV-Ray. Instead of trying to solve it, I wrote a new macro: the mesh-of-revolution. See in the next picture what it does...
... output of the test scene for the mesh-of-revolution macro.