.
An Interface for Sketching 3D Curves
Jonathan M. Cohen, Lee Markosian, Robert C. Zeleznik, John F. Hughes, Ronen Barzel.
Proceedings of the 1999 ACM Symposium on Interactive 3D Graphics, pp. 17--21,
1999. [BibTeX]
Art-Based Rendering of Fur, Grass, and Trees
Author(s): Michael A. Kowalski, Lee Markosian, J.D. Northrup, Lubomir D. Bourdev, Ronen Barzel, Loring S. Holden, John F. Hughes.
Proceedings: Proceedings of Siggraph 99,
1999.
[BibTeX] 
Abstract:
Artists and illustrators can evoke the complexity of fur or vegetation
with relatively few well-placed strokes. We present an algorithm
that uses strokes to render 3D computer graphics scenes
in a stylized manner suggesting the complexity of the scene without
representing it explicitly. The basic algorithm is customizable
to produce a range of effects including fur, grass and trees, as we
demonstrate in this paper and accompanying video. The algorithm
is implemented within a broader framework that supports procedural
stroke-based textures on polyhedral models. It renders moderately
complex scenes at multiple frames per second on current
graphics workstations, and provides some interframe coherence.
Interactive Pen-and-Ink Illustration
Michael P. Salisbury, Sean E. Anderson, Ronen Barzel, David H. Salesin.
SIGGRAPH 94 Conference Proceedings, pp. 101--108, July,
1994. [BibTeX]