@dodioflo
Hi,
I have been developing techniques for 3D in Isadora for a while. Hopefully the following experiences I have had will assist with your process. Please have a look at this post https://community.troikatronix.com/topic/2187/3d-objects-in-isadora. If there is a specific issue can you hone it in as there are numerous hurdles at the vertex modelling and texture UV stages that can make the files unusable in Isadora.
Although the above linked forum post is from half a decade ago all of the issues associated with the 3D actors in Isadora are still current!
One thing you will have to get familiar with is getting your 3D vertices and polygons per mesh to conform to the 3DS limit : 65536
I can recommend an open source application that does a good job of decimating models, to conform to the required polygon count, it is MeshLab: http://www.meshlab.net/
Blender does a better job of UV texture mapping than Cheetah. However, Blender 2.8 does not have 3DS export as yet (although I haven't looked for a couple of weeks). Because of this, there is a compromise of either going back to a previous version of Blender with legacy 3ds export, or using another program to transpose from, say, OBJ to 3DS. There has also been an issue with Blender and Isadora in terms of the encoding file paths of associated texture image files. Cheetah works well with Isadora in terms of assigning image files to UV texture maps that can then be automatically found when a 3DS file is imported into an Isadora patch.
So a workflow is possibly going to become efficient using two or three 3D programs to pass the mesh file through.
My personal workflow is.
Modelling and rigging in Blender or Cheetah 3D. Texture mapping in Blender. Exporting as OBJ. Decimating the final mesh in MeshLab to conform to a minimum number of polygons while maintaining the overall integrity of the model - so this is an optimisation step. Reassigning the texture image in Cheetah and saving as a 3DS file with linked texture map for use in Isadora.
I have made some 3D demonstration patches available through this recent forum post. https://community.troikatronix.com/topic/6540/3d-ropes-user-file/2
If you want to look under the hood at the patch, send me a private message (there is a chat feature in the top right of this forum).
I have also prepared a tutorial file about one technique for using 3D meshes in the 3D Model Particles (starts page 11) : https://community.troikatronix.com/assets/uploads/files/1536703782928-particlestutorial_small.pdf
I haven't attempted to use Maya, Cinema4D or VectorWorks to make 3DS files directly, but I would suggest exporting to OBJ and then converting to 3DS using MeshLab. This is going to be an option to try. You will then be left with having to deal with any assigned texture images and perhaps that's where Cheetah 3D comes in.
Make a feature request for Isadora to support OBJ files and if that happens, we will all be a couple of steps better off.
Kind Regards
Russell