@inproceedings{Tolba:2001:APD,
  opteditor = {},
  optnote = {},
  optorganization = {},
  author = {Osama S. Tolba and Julie Dorsey and Leonard McMillan},
  optkey = {},
  optannote = {},
  optseries = {},
  url = {http://www.cs.utah.edu/npr/papers/Tolba_i3d01.pdf},
  address = {New York},
  localfile = {papers/Tolba.2001.APD.pdf},
  publisher = {ACM Press},
  doi = {http://doi.acm.org/10.1145/364338.364342},
  optmonth = {},
  citeseer = {http://citeseer.nj.nec.com/389781.html},
  optcrossref = {},
  booktitle = {Proceedings of the ACM Symposium on Interactive 3D Graphics, I3D
               2001},
  optstatus = {doi},
  optvolume = {},
  optnumber = {},
  abstract = {We present a novel drawing system for composing and rendering
              perspective scenes. Our approach uses a projective 2D
              representation for primitives rather than a conventional 3D
              description. This allows drawings to be composed with the same
              ease as traditional illustrations, while providing many of the
              advantages of a 3D model. We describe a range of user-interface
              tools and interaction techniques that give our system its 3D-like
              capabilities. We provide vanishing point guides and perspective
              grids to aid in drawing freehand strokes and composing perspective
              scenes. Our system also has tools for intuitive navigation of a
              virtual camera, as well as methods for manipulating drawn
              primitives so that they appear to undergo 3D translations and
              rotations. We also support automatic shading of primitives using
              either realistic or non-photorealistic styles. Our system supports
              drawing and shading of extrusion surfaces with automatic hidden
              surface removal and highlighted silhouettes. Casting shadows from
              an infinite light source is also possible with minimal user
              intervention},
  title = {{A} {P}rojective {D}rawing {S}ystem},
  year = {2001},
  pages = {25--34},
}