Adaptive LOD editing of quad meshes

We present a method for editing the LOD of quad meshes, which supports both adaptive refinement and adaptive coarsening. Starting at a base mesh, we generate a quad-dominant mesh which is consistent with the Catmull-Clark subdivision. Consistency is both topological and geometrical: an adaptively subdivided mesh coincides with the uniformly subdivided mesh wherever the level of subdivision is uniform, and the limit surface is the same. Subdivided meshes contain a majority of quad elements and a moderate amount of triangles and pentagons in the regions of transition across different levels of detail. Topological LOD editing is controlled with local conforming operators, which support both mesh refinement and mesh coarsening and work on a plain mesh without the need of cumbersome hierarchical data structures.