Embodiments disclosed herein provide techniques for decomposing 3D geometry into developable surface patches and cut patterns. In one embodiment, a decomposition application receives a triangulated 3D surface as input and determines approximately developable surface patches from the 3D surface using a variant of k-means clustering. Such approximately developable surface patches may have undesirable jagged boundaries, which the decomposition application may eliminate by generating a data structure separate from the mesh that contains patch boundaries and optimizing the patch boundaries or, alternatively, remeshing the mesh such that patch boundaries fall on mesh edges. The decomposition application may then flatten the patches into truly developable surfaces by re-triangulating the patches as ruled surfaces. The decomposition application may further flatten the ruled surfaces into 2D shapes and lay those shapes out on virtual sheets of material. A person, or machinery, may cut out those shapes from physical sheets of material based on the layout.