@inproceedings{Gooch:1998:NPL,
  optcitations =
                  {Curtis:1997:CGW,Dooley:1990:AIS,Elber:1990:HCR,Haeberli:1990:PBN,Litwinowicz:1997:PIV,Markosian:1997:RTN,Meier:1996:PRA,Phong:1975:ICG,Saito:1990:CRD,Salisbury:1997:OTI,Seligman:1991:AGI,Winkenbach:1994:CGP},
  optnote = {ISBN 0-89791-999-8},
  optorganization = {},
  author = {Amy A. Gooch and Bruce Gooch and Peter Shirley and Elaine Cohen},
  series = CGPACS,
  optannote = {Phong-shaded 3D imagery does not provide geometric information of
               the same richness as human-drawn technical illustrations. A
               non-photorealistic lighting model is presented that attempts to
               narrow this gap. The model is based on practice in traditional
               technical illustration, where the lighting model uses both
               luminance and changes in hue to indicate surface orientation,
               reserving extreme lights and darks for edge lines and highlights.
               The lighting model allows shading to occur only in mid-tones so
               that edge lines and highlights remain visually prominent. In
               addition, we show how this lighting model is modified when
               portraying models of metal objects. These illustration methods
               give a clearer picture of shape, structure, and material
               composition than traditional computer graphics methods.},
  editor = {Michael Cohen},
  url = {http://www.cs.utah.edu/~gooch/SIG98/abstract.html},
  address = {New York},
  localfile = {papers/Gooch.1998.NPL.pdf},
  optkeywords = {illustration, non-photorealistic rendering, silhouettes,
                 lighting models, tone, color, shading},
  publisher = {ACM Press/ACM SIGGRAPH},
  optmonth = jul,
  doi = {http://doi.acm.org/10.1145/280814.280950},
  citeseer = {http://citeseer.nj.nec.com/gooch98nonphotorealistic.html},
  booktitle = SIGGRAPH98,
  optstatus = {OK},
  title = {{A} {N}on-{P}hotorealistic {L}ighting {M}odel for {A}utomatic
           {T}echnical {I}llustration},
  year = {1998},
  pages = {447--452},
}