Antennavis is a OpenGL antenna visualisation toolkit for nec2.
This software was written by Kenneth E. Harker, WM5R in 1998. I liked the 3D images of the presented antenna patterns on Kenneth's web-site so much that I have put some effort into creating a useable software package out it.
So I contacted Kenneth to ask him how he thought about further development. Ken agreed to put up a project page and website for future versions. The project page is available at Savannah.
This package provides a tcl script called antennavis which makes use of the provided TkAnt widget. Antennavis will expect a nec2 binary somewhere in your path. The nec2 binary you are using should take filenames for arguments, e.g. "nec2 input.nec output.nec". In case you can't meet these requirements, you can download a statically linked nec2 version from: qsl.net or mattsnetwork.