`fieldcraft_mesh::octree::octree_hex_mesh` meshes any closed part with hex8 only:
- an adaptive 3-refinement grid (27-tree) with strong balance and closure, filled with
conforming node-marking transition templates (Schneiders; checked over all 48 symmetries);
- a core of grid cells kept clear of the boundary (the HybridOctree buffer rule), with
non-manifold cleanup and a genus check against the part;
- a feature graph from the B-rep (corners, curves, patches) and a partition-first map of the
core's boundary onto it, then two boundary layers: a padding layer and a pillow per patch,
so every face boundary and sharp edge is captured by element edges;
- a Garanzha-type untangling and fitting energy (shape term |J|^3/chi, a volume term and a
soft fitting term, deterministic across platforms), a compass search on the worst
elements and a certified repair; failures refine the grid near them and rebuild, within
bounded attempts and growth.
The output passes the certified Jacobian check of every element and a gate that the
boundary encloses the elements' volume; boundary quads carry their B-rep faces. Quality is
reported with the same scaled Jacobian as mesh.quality. Literature notes for each step are in
docs/meshing/literature.md (B1.6-B1.10).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm
