Reconstructing line drawings from wings: The polygonal case

Object wings are 2 1/2-D primitives encoding fragments of object boundary and the adjacent surfaces. The adequacy of wing representation for polygonal scenes is demonstrated in the sense that if a wing representation has been derived from the image of polygons, the spatial structure of the view can be uniquely recovered. In other words, it is possible to reconstruct all visible parts of the scene based on the given wing representation--all visible vertices, the equations of all visible faces, and the completely labeled line drawing of the scene. It is shown that not only can most origami and polyhedral objects be handled but also that many views considered 'accidental' by other researchers can be handled as well.