Computer-Generated Pen-and-Ink Illustration of Trees
Author(s): Oliver Deussen, Thomas Strothotte.
Proceedings: SIGGRAPH 00,
2000.
[BibTeX] 
Abstract:
We present a method for automatically rendering pen-and-ink illustrations
of trees. A given 3-d tree model is illustrated by the tree
skeleton and a visual representation of the foliage using abstract
drawing primitives. Depth discontinuities are used to determine
what parts of the primitives are to be drawn; a hybrid pixel-based
and analytical algorithm allows us to deal efficiently with the complex
geometric data. Using the proposed method we are able to
generate illustrations with different drawing styles and levels of abstraction.
The illustrations generated are spatial coherent, enabling
us to create animations of sketched environments. Applications of
our results are found in architecture, animation and landscaping.