SH-Cubes: Differentiable Isosurface Extraction from Continuous Anisotropic Fields via Spherical Guidance

High-Fidelity Iso-Surface Extraction via SH-Cubes. As shown on the left, unlike Marching Cubes and FlexiCubes [Shen et al. 2023], which rely on isotropic scalar samples, and TetWeave [Binninger et al. 2025], which adopts a discrete anisotropic formulation, SH-Cubes introduces a continuous anisotropic formulation for isosurface extraction. This enables SH-Cubes to preserve high-frequency details and sharp geometric features, producing consistently high-quality isosurfaces across a wide range of sampling resolutions, as shown in the right panels. By comparison, state-of-the-art methods show different limitations: FlexiCubes exhibits geometric aliasing and less accurate sharp structures on coarser grids (64³), while TetWeave shows subtle surface fluctuations in otherwise smooth regions, even at comparable or higher resolutions.