This question may have been asked before, but how do I create shadows in DS4(Advanced) by using a photo background to insert Vicky into instead of a 3D modeled environment?

Take for instance the Sand & Water Beach photos below, or any that I have taken myself. Here's an example of the S&W package available from DAZ:

http://www.daz3d.com/i/shop/itemdetails/?item=6947

If I understand correctly, they are just regular 2D photos someone is offering for DAZ users as backdrops.

I have been practicing poses with my Vicky4 and using some of my own vacation photos and a few work pics too using backdrops under Edit/Backdrop. But even with Shadows & other things all turned ON in DS4, I'm not getting any shadows on the floor or walls or bed, beach, pool, etc. I also need reflections too. But that's another problem for another day perhaps. Unless you want to add some info there too. I won't discourage it.