[brett19]

This follows up the 9 cases #685 parked in known_mismatches.toml. Status: draft. The root cause is found, but the fix is blocked on a larger port (see below).

Root cause

• topology_traverser::is_inner_shell ran its rays and GetPointsInFace on a b.clone() scratch copy.
• points_in_face ran CalculateUVDomainFromUVTrimCurves and its iso-line CurveOnClassify on further copies.
• Upstream's const face queries leave the UV trim curves they create on the B-rep, so C++ exported stored trims that Rust lacked. For brep_p6 two_disjoint_cubes, geom.len was cpp 1385 vs rust 1232.
• Found by logging every set_uv_trim_curve with its B-rep address: 15 trims landed on the final B-rep and 18 on copies, all of them from is_inner_shell.

What this branch does

• is_inner_shell, points_in_face and Shell::is_inner_shell take &mut Brep and run on the caller's B-rep.
• The iso-line classification copies the UV trims, tolerance growth and gap caches back from its CurveOnClassifyCache snapshot.

Results:

• topology.brep_p6 make_face.json#89..95: geometry and topology now match C++ exactly. Only the Mark2 counter still differs. Upstream IntersectTSBound takes its trimmed-cache branch with SmNewMarkAndLock (SmCurveClass.cpp:16242), while the port walks the loop uses. These 7 cases stay known mismatches with that reason.
• The skin cases (skin_concentric_loops, skin_primitive_annular), plus creation_p2 gen0201/gen0214, now defer at TrimSrfCache::build_tree_with_face for a face-owned surface. Their known-mismatch entries are removed.
• topology.shell reaches 911/911 pass locally.

Blocker

• topology.topology_traverser is green on main. With this branch, 14 of its op-7 (IsInnerShell) cases go from pass to deferred at SmFace handle of a surface's face (topology.face_p2).
• Why: the scratch copy came from Brep::clone, which drops geometry owners (see fix: B-rep copies keep geometry owners #681). The ray's surface looked free, so an untrimmed cache was built. On the real B-rep, the face-owned surface needs a face-bound trimmed cache, and global_line_intersect_held's RaySurface handles don't bind one.
• Probes ruled out the copy-backs: neither undoing the UV-domain change nor undoing the snapshot copy-back removes these deferrals.
• Proposed fix:
  • Give global_line_intersect_held / the IsInnerShell ray world a face-bound trimmed surface cache, as smsurf_GetSurfaceCache builds.
  • Port IntersectTSBound's cached branch with its mark, which needs &mut Kernel.
  • That would clear the traverser deferrals, the skin build_tree_with_face deferral and the brep_p6 Mark2 counter together.
• fix: B-rep copies keep geometry owners #681 overlap: fix: B-rep copies keep geometry owners #681 plans to make these same library copies keep owners (including is_inner_shell's). That would hit the same deferral, so the two need to be coordinated.

Local checks on 165745d64: fmt, clippy -D warnings, cargo test -p solidcore (2079 lib tests) and wasm all pass.

PARTIAL topology.brep_p6 cases=595 passed=588 failed=0 deferred=0 known_mismatch=7
PASS    topology.shell cases=911 passed=911 failed=0 deferred=0
PARTIAL topology.topology_traverser cases=909 passed=895 failed=0 deferred=14   <- green on main (regression)
PARTIAL topology.face_p2 cases=2692 passed=2596 failed=0 deferred=96
PARTIAL query.face_p2 cases=1344 passed=1326 failed=0 deferred=18
PARTIAL topology.brep_p7 cases=348 passed=289 failed=0 deferred=59
PARTIAL primitive.primitive_creation_p2 cases=328 passed=234 failed=0 deferred=74
PARTIAL sweep.api_surfaces cases=882 passed=881 failed=0 deferred=1

🤖 Generated with Claude Code

[brett19]

@bherbruck, could you tell me why this was closed? Was it because #697 seemed to supersede it? #697 fixed the traverser deferrals that blocked this PR, but this branch still adds the &mut IsInnerShell / PointsInFace route, which makes topology.brep_p6 green (595/595) and clears 7 region-nesting known mismatches. I've reopened it as #714, merged with #697 and the latest main. If there's a reason this direction shouldn't land, let me know and I'll close that one too.

🤖 Generated with Claude Code