Multi-scale line drawings from 3D meshes

We present a method to view-dependently control the size of shape features depicted in computer-generated line drawings of 3D meshes. Our method exhibits good temporal coherence during level of detail transitions, and is fast because the calculations are carried out entirely on the GPU. The strategy is to pre-compute, via a digital geometry processing technique, a sequence of filtered versions of the mesh that eliminate shape features at progressively larger scales. Each filtered mesh retains the original connectivity, providing a direct correspondence between meshes.At run-time, the meshes are loaded onto the graphics card and a vertex program interpolates curvatures and positions between corresponding vertices in adjacent meshes of the sequence. A fragment program then renders silhouettes and suggestive contours to produce a line drawing for which the size of depicted shape features follows a user-specified "target size". For example, we can depict fine shape features over nearby surfaces, and appropriately coarse-scaled features in more distant regions. More general level-of-detail policies could be implemented on top of our approach by letting the target size vary with scene attributes such as depth, image location, or annotations provided by the scene designer.