When modelling buildings and other features, it would be great to be able to convert a point cloud or 3D model to a set of discrete planes and 3D geometry. This would require edge detection to create a line along the intersection of two planes, and a way to create planes to model flat surfaces.
The first step to achieving this is going to be planimetrics which I know there has been some work on. You have to have grade breaks before you can create planes. Especially when you have to decimate the mesh to create good planes.