Very large volumetric meshes are of crucial importance in many areas such as large-scale computational fluid dynamics (CFD) simulations, whether for car engine design or for simulating oil and gas reservoirs. Recent computational advances have led to computational grids of extreme size, such as trillion-cell reservoir simulations. The size and complexity of such grids pose a tremendous challenge to interactive visualization and analysis, and require the development of novel data structures for visualization, e.g., polyhedral grid data structures, as well as data structures for efficient querying and analysis.