NPR Line Drawing
Hertzman, Curve Analogies, 13th Eurographics Workshop on Rendering, pp. 233-246(2002) Strassman, S., Hairy brushes, SIGGRAPH '86 Hsu, S.C., Skeletal Strokes, Proceeding of the 6th annual ACM symposium on User interface software and technology S. Saito, Curvature-based stroke rendering, Visual Comput (2008)
2010. 1. 10.