A method, device, and computer-readable storage medium for generating a proxy mesh. The method includes: receiving an input polygonal mesh that includes multiple sub-meshes, each of which is a polygonal mesh, where the input polygonal mesh is a computer representation of a three-dimensional (3D) object; generating a voxel volume representing the input polygonal mesh, wherein the voxel volume comprises voxels that approximates a shape of the 3D object, wherein a first set of voxels of the voxel volume includes voxels that are identified as boundary voxels that correspond to positions of polygons of the multiple sub-meshes of the input polygonal mesh; determining a grouping of two or more sub-meshes that together enclose one or more voxels of the voxel volume other than the voxels in the first set of voxels; and generating a proxy mesh corresponding to the input polygonal mesh based on the grouping of two or more sub-meshes.