480 CHAPTER 14. THREE-DIMENSIONAL DRAWINGS
of paper. This can be achieved by using projections. In computer graphics the most
commonly used projections are the parallel and perspec ti ve projections. A 2D image, by
its very nature, will necessarily contain less information than the original 3D drawing. It is
therefore desirable to find viewpoints (the position and the direction the viewer is facing)
that r es u lt in “nice” 2D images, that is, pr ojections th at pres er ve as much information
about the 3D drawing as pos s ibl e. Having an edge of the 3D drawing map to one point in
the projection is lossy in that context, as is having two vertices proj ec t to the s ame point.
Bose et al. [BGRT99] developed an algorithm that, given a 3D straight-line ...