Mahdavi-Amiri, AliHarrison, ErikaSamavati, Faramarz2016-04-012016-04-012016-04-01http://hdl.handle.net/1880/51137Hierarchical grids appear in various applications in computer graphics such as subdivision and multiresolution surfaces, and terrain models. Since the different grid types perform better at different tasks, using simple conversions, we can switch between the grid types to take advantages of each grid for better supporting advanced applications. In this paper, we introduce some simple conversions between grids. To describe their usage, we define new regular and semiregular refinements. We also describe how patch-based data structures can be used for hexagonal cells and semiregular refinements.enRefinementsGrid ConversionPatch-based Data StructuresTransformationsSemiregularSubdivisiontechnical report10.11575/PRISM/30991