View-Dependent Particles for Interactive Non-Photorealistic Rendering
Derek Cornish, Andrea Rowen, David Luebke.
Graphics Interface (GI'01), June,
2001. [BibTeX]
Volume Illustration: Non-Photorealistic Rendering of Volume Models
Penny Rheingans, David Ebert.
IEEE Transactions on Visualization and Computer Graphics, Vol. 7, No. 3, pp. 253--264, July-Sept,
2001. [BibTeX]
Volumes of Expression: Artistic Modelling and Rendering of Volume Datasets
Author(s): S. M. F. Treavett, Min Chen, R. Satherley, M. W. Jones.
Proceedings: Computer Graphics International (CGI'01), Hong Kong, China, July 03 - 06,
2001.
[BibTeX] 
Abstract:
This paper presents the design and implementation of artistic effects in modelling and rendering of volume datasets. Following different stages of a volume-based graphics pipeline, we examine various properties of volume data, and illustrate how expressive and non-photorealistic effects can be implemented. We demonstrate that the true 3D nature of volume data makes it particularly applicable for this use, allowing the addition of complex effects at the modelling stage as well as during rendering.
Walk-Through Illustrations: Frame-Coherent Pen-and-Ink Style in a Game Engine
Bert Freudenberg, Maic Masuch, Thomas Strothotte.
Computer Graphics Forum (EG'01), Vol. 20, No. 3, pp. 184--191,
2001. [BibTeX]