External memory simplification of huge meshes

Very large triangle meshes, i.e. meshes composed by millions of faces, are becoming common in many applications. Obviously, these complex meshes introduce severe overhead in transmission, rendering, processing and archival. Mesh simplification and LOD management have become a mature technology that in many cases can efficiently reduce the above overhead. But none of the available systems can manage meshes characterized by a huge size: RAM size is always a severe bottleneck. In this paper we present a system able to manage huge meshes on PC-based platforms, that supports mesh editing, simplification and detail preservation. The system represents the data using a hierarchical data structure called OEMM, which allows to maintain the data on external memory, to load dynamically in main memory only the active sections and to preserve data consistency during local updates. The system supports management and simplification of up to O(10^9) triangles meshes. The time overhead due to the external memory management are affordable. Results of the test of our system on complex meshes are presented.