Thanks! Are you using Tolk library? I'm using Tolk with python. Before knowing BrushTone, I was attempting to create a program for image manipulation in a BlindFriendly Version. I've some ideas and BrushTone can be a preliminary step. I seen 3daudimesh, but I don't have .stl file to try it and, with 3daudimesh I can't create 3d graphics; so, I don't know how it works.
BrushTone is the first version, I've been working on a new tool as time allows which will include a number of improvements and new features. There are a few other drawing tool's i've found around that you may also be interested in: SVGDraw01, BlindPaint, and TactileView. If your interested in any python examples or source code for OpenAL or Peter Meijers Sonifer method I have a bunch freely available in a repository.
As for AudiMesh3D, its more of a preliminary tool for only viewing 3D models, when you start it there's a default cube you can view so you don't strictly need a 3D model to use it. The interface is similar to that in BrushTone, though you can rotate, scale, and pan around the 3D model however you like. Its largely meant to be used with OpenSCAD, a free 3D CAD modeling program that uses text based scripting, there's a description in AudiMesh3D's documentation on how to use it with it. Essentially, what you can do is write a text based script file, then compile it into an STL file on the command line with OpenSCAD, then view it with AudiMesh3D.
Also, if you haven't already you should consider dropping by the audiogames.net community.