Software/Modeler for Operations Research wanted

[Michel Hafner]

I'm looking for Software suited to visualize optimization problems. For example
it should be able to display a region of 3D-space defined by convex
restrictions and surfaces of the target-function with constant function-value,
so that you can show how an algorithm works and gets to the optimum. The
problem is that conventional 3D-modelers offer no help to construct this kind
of mathematically defined objects. 
If you know a Software suited to this kind of problem please e-mail me.
The software should be portable to workstations of Silicon Graphics.