Emil Praun, Hugues Hoppe, Matthew Webb, Adam Finkelstein
Appears in SIGGRAPH 2001
Drawing surfaces using hatching strokes simultaneously conveys
material, tone, and form. We present a real-time system for non-photorealistic rendering of hatching strokes over arbitrary
surfaces. During an automatic preprocess, we construct a sequence of mip-mapped hatch images corresponding to different tones,
collectively called a tonal art map. Strokes within the hatch images are scaled to attain appropriate stroke size and density at
all resolutions, and are organized to maintain coherence across scales and tones. At runtime, hardware multitexturing blends the
hatch images over the rendered faces to locally vary tone while maintaining both spatial and temporal coherence. To render strokes
over arbitrary surfaces, we build a lapped texture parametrization where the overlapping patches align to a curvature-based direction
field. We demonstrate hatching strokes over complex surfaces in a variety of styles.
Download: paper (5.75Mb PDF) video(44Mb, WindowsMedia) Presentation (4Mb ppt). Copyright ACM 2001.