Siggraph Paper Summary: Rendering Parametric Surfaces in Pen and Ink by Georges Winkenbach & David H. Salesin, University of Washington

I can still remember the first SIGGRAPH I attended in 1996. By the generosity of MTV Networks, I had a full conference pass which meant conferences and papers (which I barely attended) and the full set of publications, which I devoured eagerly afterwards. This paper really blew my mind, and I still think it’s a technique with a lot of potential that hasn’t been well exploited. Way cooler than

Winkenbach’s paper presents what looks like a robust technique for inking parametric (i.e. NURBS) surfaces. Ink line direction is controlled by surface parameter, the tone by modulating stroke thickness. Strokes can be sharp or wiggly, short strokes become stippling. Tone can be controlled by lighting (they present a technique for shadows), by texture map, or something else (i.e. reflection mapping).

The technique could probably be adapted to utilize UV mapping coordinates. The authors tantalizingly suggest generating strokes “along directions that aremore intrinsic to the geometry of the surface—for example, along directions of principal curvature.” Not addressed as far as I can tell is temporal coherence. What does this technique look like over a series of frames, when the surface is translating and deforming?

This approach is not available in any commercial package that I am aware of, but I wish it were.