AI Seminar
  -------------------------------
  Tuesday, February 8th, 2005
  4:00 pm - 5:30 pm
  175 ATL (Large Conference Room)

  "Detail Control in Line Drawings of 3D Meshes"
  Kyuman Jeong and Alex Ni (co-work with Prof. Lee Markosian)
  Artificial Intelligence Laboratory
  University of Michigan

===============================

In most NPR research, strokes are drawn mainly along silhouettes
and other important shape features, and little or no shading is used.
Previous work has the problem of rendering each stroke with almost
full detail.  Our research goal is to depict shape features at a
desired scale. For example, when mesh triangles project into the image
plane at sub-pixel sizes, both suggestive contours and silhouettes may
form dense networks that convey shape poorly.

The solution we propose is to convert the input mesh to a
multi-resolution representation (specifically, a progressive mesh), then
view-dependently refine or coarsen the mesh to control the size of its
triangles in image space.  We thereby control the scale of shape features
that are depicted via silhouettes and suggestive contours. We propose a
novel refinement criterion that achieves this goal, and we address the
problem of maintaining temporal coherence of suggestive contour and
silhouette paths when extracting them from a changing mesh.