A modeling system includes a controller in communication with a memory, the memory including a unit cell defined by a unit cell structure and a control voxel, wherein the unit cell structure is mapped to the control voxel. The controller is configured to: divide a three-dimensional geometry into a plurality of voxels; and populate each voxel with a corresponding unit cell. For each voxel, the corresponding unit cell structure is modified to fit within each voxel according to the mapping of the unit cell structure to the control voxel surfaces by positioning the unit cell structure relative to the voxel surfaces corresponding to the control voxel surfaces of the mapping. At least one of the voxels of the plurality of voxels has a voxel shape that is different than a control voxel shape of the control voxel.