Mesh Collision in 3D view?

Hi guys. I am wanting to make a series of meshes in Blender that ‘collide’ with each other upon movement in the 3Dview window (during editing, not in BGE). I have messed around a good amount, but cant seem to find any constraint or modifier that does such a thing. I imagine there might be a different way to go about this (other than constraint/modifier), so my ears are open. Just for the record, I realize my request is a little specific. To give a brief explanation, I am making a small exe that will run alongside Blender to make Blender function as a map-editor for a game I am making, and the piece-collision issue is to prevent users from placing multiple pieces in the same spot. Any help would be much appreciated. Thanks.