This is a nice tutorial, but it seems a bit kludgey (and I'm guessing part of that is due to Fusion 360's "not quite a fully finished CAD system," though they are making pretty good progress with it, and I find it's a fairly nice program, especially for the price, (free to hobbyists) and it includes CAM abilities.)
I would think OpenSCAD would be pretty decent at this, but honestly, I've never tried making parabola's or similar with it.
If you had a specific design in mind, it might actually be more satisfying to generate the STL triangles directly. You can fit your parabola in 2D (by, say, computing reflection angle to a fixed focal point), then just rotate and dump out STL.
ok for the 3d printing of the "structure" but then how to make it reflective? do you use regular allumination chamber or what technique ? which precision you can achieve to validate the prototype ?
Print your model in ABS. Smooth it by putting it in a paint can on a little stand with some acetone soaked rags below for about 1/2 hour. Paint with some of this paint. You will be amazed.
Although the laser sintering printer downstairs produces quite nice surface finishes. Not good enough for an optical mirror, but definitely good enough for mm-wave antennas.
I would think OpenSCAD would be pretty decent at this, but honestly, I've never tried making parabola's or similar with it.
A quick google found this openscad script for parabolas: http://www.thingiverse.com/thing:84564