could you use a gaming engine to make an animated movie? but not like machinima(3d models/characters) ? something like unity engine
its mainly for camera angles and pans around 2d art, or people use after effects???
South Park was animated in Autodesk Maya. It's not impossible, but it's not necessarily the most practical way to go about it. As for Unity, aren't there already a lot of (indie) 2D games developed with that?
You could, but it would be clunky,
The results would be better for something experimental really. Unity has some interesting features that would be good for it, it gets decent results with the new lighting model, there is built in physics. It would run at real time...its very artist friendly. You could get your 3D assets in their pretty painlessly. You can layer multiple cameras....
But really, Cinema4D is probably what you'd really be looking for.
If you just want to matte together 2D art then AE or hell Photoshop itself has some well hidden animation functions using a feature called "Video Layers" They give surprisingly good results.
Pretty sure they still use Maya even now. Trey seems to make a point of challenging the artists to do cool camera tricks for episodes according to the documentaries (Specifically the one in the Pandemic episodes). Definitely not a typical show to use as an example though.