1. A computer-readable storage medium storing computer-executable instructions for causing a computer system programmed thereby to perform a method of generating a multi-chart geometry image, the method comprising: partitioning a mesh into a plurality of charts with geometrically natural boundaries; and packing the plurality of charts into a single geometry image as irregular polygons having arbitrary shapes based on the geometrically natural boundaries; wherein the partitioning comprises iteratively: growing the plurality of charts from seeds by assigning mesh faces on the mesh to one of the plurality of charts; and updating the seeds for the plurality of charts.