   3D elements in a 2D environment.
  I'm interested in creating a game with a map system similar to that of FF7. Where the environment is primarily 2D. With some 3D elements(such as characters). I've written an isometric engine before, but I'm not sure if an isometric engine is sufficient or too much. I just can't figure out how collision would work.Here's a ss of FF7's mapping system:http://bulk2.destructoid.com/ul/137223-barr.jpgNotice 2D environment(which looks 3D), and 3D characters & a couple scene elements.   
  The 2D environment is just an overlaid image; it's still a 3D engine.  Each scene that the characters can run around in contains basic 3D level geometry, which is interacted with but not drawn.  instead, each scene has a fixed camera point, so that a 2D image can be on top that will appear to be the environment the player is running around in.   