Hi David,
actually yes, i did, but i didn't manage to do the editing and producing it. I was not sure if this is interesting to someone, because it is quite manufacturer specific flow: have an existing model and "only" do modifications, optimizations to it, specifically to GDTF.
Also, fun fact, depending on exact inside rotation of the 3D model, my "quick rotations" done via swapping axes is, while 99% the same, occasionally 90° off, meaning i must use different axes for the swap/rotate.
Yes, this is Linux, i only reboot to Win when i want to see GDTF in MA3 3D or Vision, so that is a bit clumsy, although at times i use a second computer for just that, because rebooting into strange OSes is not fun. Maybe one day we'll get Linux build of MA3 :))
As for the tools i use, Freecad is really good and usable, it has quirks, but as i do not do complex editing but mostly splitting or extracting parts it is very good. So i can for example take only part of a given 3D file, like some of the front lenses, motion camera or other. The rest is done via Meshlab, where i "only" do the rotations, origin setting and mainly the mesh simplification + export. I have not found how... invested time into making this all work only in one of them or for example in Blender but there is also an issue with importing, export to 3DS and other... the workflow i have has been very fast, stable and predictable (key factors for me).
The mesh simplification is a key for GDTF. It took me some time to find Meshlab which does all these things in a fast way. There is Decimate modifier in Blender, and although i have done some (mostly animation) work in Blender, i didn't try using Blender in my GDTF work flow. I am sure C4D has something similar. Mesh simplification is really important. This is because for the most, many people presume that the model has to be as precise and as "nice" as possible, while the opposite is required for 99% of the time and we have been getting a lot of heat for "your models are too complex" over the years - if you patch few hundreds of single unit with model too detailed, planning/pre-viz tools slow down to crawl... I am sure there are custom projects where one wants to build a real-world render with textures, smooth models... and, GDTF is extensible enough to make it possible to use for that and even more in the future (for example by allowing multiple versions of models, adding textures...) , but the initial focus has been on the most required work-flow, so our [Robe] model optimizations are hitting exactly that.
?
P.