This answer represents a bit of a convoluted process, but I believe it would work for you and meets a couple of your requirements.
OpenSCAD is a free program that allows for command line interface. OpenSCAD also has a feature involving animation. This particular link is rather limited with respect to useful information, but my search results for "OpenSCAD animation" resulted in too many from which to choose. Most of the other links were far more comprehensive, including one from Instructables.
One complication in this answer is that the files would have to be converted from .OBJ to .STL in order to be imported and processed. I suspect there are CLI programs capable of doing batch conversions to make that portion easier, but I did not research it.
Additionally, the output is going to be one image in .PNG format per frame, which would have to be converted to .GIF or loaded into a video editor to create "standard" video. There's a web site in which this process is explained in a limited manner which involves using ImageMagick convert utility which is a CLI.
The animation above is from the linked web site. A number of features of OpenSCAD have been implemented in this example, as the rendered objects are usually single color and not semi-transparent.