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Real-time ray tracing of animated skeletal characters is a persistent performance challenge. Bounding Volume Hierarchies (BVHs) must be updated every frame as geometry deforms, and while refitting is cheap, it degrades ray throughput under large deformations because general-purpose builders may group triangles across deformation boundaries, causing bounding nodes to expand around diverging geometry.

We introduce Bone-Dominance Partitioning, a preprocessing method that decomposes a skinned mesh into clusters of triangles driven by the same bones, each assigned an independent BVH subtree. Lower-level nodes thus contain only triangles that deform together, preserving tightness under refitting. The method requires no animation data and no changes to the per-frame pipeline.

We evaluate Bone-Dominance Partitioning across five skeletally animated scenes against full rebuilds and standard refitting approaches. Most scenes exhibit only modest deformation and show a small but consistent overhead due to increased leaf depth. However, for an adversarial scene featuring tightly folded initial geometry, Bone-Dominance Partitioning largely mitigates catastrophic refitting degradation, reducing the secondary ray throughput coefficient of variation from 0.676 to 0.121, delivering an average secondary ray speedup of 2.31×, and improving worst-case throughput by 3.49× over standard refitting.

To be able to perform a fair evaluation on real hardware, we developed a portable Vulkan-based ray tracing simulator replicating the binary BVH format of AMD's RDNA2 architecture and the traversal kernel of the Linux Mesa driver, enabling arbitrary BVH structures to be injected and measured with realistic memory and divergence characteristics.