Hardware Support for Non-photorealistic Rendering
Author(s): Ramesh Raskar.
Proceedings: Graphics Hardware, Los Angeles, CA, USA, August,
2001.
[BibTeX] 
Abstract:
Special features such as ridges, valleys and silhouettes, of a
polygonal scene are usually displayed by explicitly identifying
and then rendering ‘edges’ for the corresponding geometry. The
candidate edges are identified using the connectivity information,
which requires preprocessing of the data. We present a nonobvious
but surprisingly simple to implement technique to render
such features without connectivity information or preprocessing.
At the hardware level, based only on the vertices of a given flat
polygon, we introduce new polygons, with appropriate color,
shape and orientation, so that they eventually appear as special
features.