OffsetCrust: Variable-Radius Offset Approximation with Power Diagrams

OffsetCrust is aimed at a long-standing gap in geometry processing: offset surfaces where the radius changes across the base surface. Constant-radius offsets are comparatively well understood, but once the radius varies, the usual assumptions break down and reconstruction gets messy fast. The paper proposes a framework that computes a power diagram from contributing sites made of sampled points on the surface and corresponding off-surface points displaced in radius-dependent directions.

The practical detail that stands out is that, in the constant-radius case, those displacement directions line up exactly with the surface normals, but that alignment no longer holds generally. To deal with the resulting crust-style errors, the authors add a lightweight fine-tuning pass to reduce misalignment. That suggests the method is trying to stay computationally manageable rather than turning into a heavy optimization pipeline.

Why game developers should care: variable-radius offsets show up anywhere you need controllable thickness, shelling, brush-like modeling, coverage-style motion planning, or reconstructing surfaces from medial axis data. If you build modeling tools, procedural mesh generators, or offline geometry utilities, this is the kind of paper that can influence how you approximate variable-width extrusion, erosion/dilation, or reconstruction from sparse geometric representations.

The paper was submitted July 15, 2025 and revised June 5, 2026. The authors report experiments showing both accuracy and efficiency, plus a reconstruction use case for recovering original...