1. A method comprising: receiving a fine mesh as input representing a 3-Dimensional (3D) model and comprising first fine-mesh polygons and second fine-mesh polygons; grouping the first fine-mesh polygons into a first near-planar region of a coarse mesh and the second fine-mesh polygons into a second near-planar region of the coarse mesh, wherein the first near-planar region comprises a first coarse-mesh polygon corresponding to the first fine-mesh polygons and the second near-planar region comprises a second coarse-mesh polygon corresponding to the second fine-mesh polygons; applying a deformation to the coarse mesh, wherein applying the deformation the coarse mesh comprises increasing or decreasing an angle between the first coarse-mesh polygon and the second coarse-mesh polygon based on the first coarse-mesh polygon and the second coarse-mesh polygon respectively being in the first near-planar region and the second near-planar region; transforming the deformation into a modification for the fine mesh; and applying the modification to at least some fine-mesh polygons of the first fine-mesh polygons and the second fine-mesh polygons.