@sundialsvc4 normally I would disagree with that severely Because I love realisim, but you are right, this particular scene is more of a fantasy and things don’t have to look super-real (but the work of the actors are top notch). That’s why I resorted to motion tracking those elipses.
Back to the topic at hand, one thing that my mind instantly keeps latching on to when it sees a 2D image that needs 3D shadows, is that it asks “why is there no plugin or feature to simply take the bottom-most pixels of a group of pixels and auto-generate a 3D like drop shadow with skew???” Identifying each group of pixels to be an actor or object on a 2D image with alpha (one taken of actors on a green screen and keyed out) should be easy programmatically.
Look at GIMP’s mask grow and shrink feature, I’m sure a few lines of code can check for any pixel and check if there is no opaque pixel below it, thus identifying it as a bottom most pixel and thus all neighboring side and top pixels are that of one actor or object.
Anyways, just wishful thinking right now. Thanks for everyone’s help!