Rapid simplification of multi-attribute meshes

We present a rapid simplification algorithm for meshes with multiple vertex attributes, targeted at rendering acceleration for realtime applications. Such meshes potentially feature normals, tangents, one or more texture coordinate sets, and animation information, such as blend weights and indices. Simplification algorithms in the literature typically focus on position-based meshes only, though extensions to handle surface attributes have been explored for those techniques based on iterative edge contraction. We show how to achieve the same goal for the faster class of algorithms based on vertex clustering, despite the comparative lack of connectivity information available. In particular, we show how to handle attribute discontinuities, preserve thin features, and avoid animation-unfriendly contractions, all issues which prevent the base algorithm from being used in a production situation. Our application area is the generation of multiple levels of detail for player-created meshes at runtime, while the main game process continues to run. As such the robustness of the simplification algorithm employed is key; ours has been run successfully on many millions of such models, with no preprocessing required. The algorithm is of application anywhere rapid mesh simplification of standard textured and animated models is desired.