Knodt, JulianGao, XifengMasia, BelenThies, Justus2026-04-172026-04-1720261467-8659https://diglib.eg.org/handle/10.1111/cgf70411https://doi.org/10.1111/cgf70411Creation of collision objects for 3D models is a time-consuming task requiring modelers to manually place primitives such as bounding boxes, capsules, spheres, and other convex primitives to approximate complex meshes. While automatic convex decompositions using convex hulls exist, they are often impractical for performance-sensitive applications such as games. We propose a bottom-up approach that decomposes meshes into convex primitives designed specifically for rigid-body simulation, inspired by quadric mesh simplification. Our method fits primitives to complex meshes while guaranteeing enclosure of the original surface. Experiments on over 60 models from Sketchfab demonstrate that our approach achieves lower one-way mean and median Hausdorff and Chamfer distances compared to V-HACD and CoACD while requiring less than one-third of the collider complexity. Additionally, rigid-body simulation performance measured by wall-clock time improves consistently across tested models.CC-BY-4.010.1111/cgf.7041124 pages