This is a cut-away model of a plastic injection molding assembly, showing a complex mixing screw, barrel, endcap, nozzle body, nozzle tip, spline coupler, heating bands, and thermocouples.  It was modeled in AutoCAD and exported as a series of .3DS files.  The .3DS files were converted into a mesh of POV smooth triangles with PolyTrans, and rendered with POV-Ray.  If you ever wondered how they make all the neat plastic stuff you see all the time, this is how.