Please with model and modeling

I'd like some guidance on how to modify models. I know the models are .o3d files, but what can I use, Blender or 3ds Max? I'm a beginner, and I'd like to convert a static object like a tree or chest into a moving object (mvr_). I've been converting them to .dae files with the Model Editor and then importing them into Blender, but once I edit and save them and bring them back to the Model Editor, they don't show up. The animation I added was static, just a bone, no movement. I just wanted to convert it to an (mvr_) type. Any ideas or guidance would be greatly appreciated. Thanks to anyone who works with models.

You can use just about any 3d software that is able to export as dae, fbx or obj. Also, in the v21.2 source release, they do include official plugins for earlier version of 3ds max that could be ported over.

For the porting using Atools model editor, you need to make sure that bones are set to bones and for animation, you need to make sure each frame is keyframed for each bone, and you need to have an animation prefix to the model (Eg. Mvr_).