fix(assembly): classify datum plane references in Distance joints #315

forbes · 2026-02-22T18:23:45Z

forbes commented

2026-02-22 18:23:45 +00:00

When a Distance joint references a datum plane (XY_Plane, XZ_Plane,
YZ_Plane), getDistanceType() failed to recognize it because datum
plane sub-names yield an empty element type. This caused the fallback
to DistanceType::Other → BaseJointKind::Planar, which adds spurious
parallel-normal residuals that overconstrain the system.

For example, three vertex-to-datum-plane Distance joints produced
10 residuals (3×Planar) with 6 mutually contradictory orientation
constraints, causing the solver to find garbage least-squares
solutions.

Add early detection of App::Plane datum objects before the main
geometry classification chain. Datum planes are now correctly mapped:

Vertex + DatumPlane → PointPlane → PointInPlane (1 residual)
Edge + DatumPlane → LinePlane → LineInPlane
Face/DatumPlane + DatumPlane → PlanePlane → Planar

Summary

Changes

Checklist

Commit messages follow conventional commits (feat:, fix:, chore:, docs:, art:)
Code follows project style (clang-format for C++, black for Python)
Changes are tested locally
Documentation updated (if applicable)

When a Distance joint references a datum plane (XY_Plane, XZ_Plane, YZ_Plane), getDistanceType() failed to recognize it because datum plane sub-names yield an empty element type. This caused the fallback to DistanceType::Other → BaseJointKind::Planar, which adds spurious parallel-normal residuals that overconstrain the system. For example, three vertex-to-datum-plane Distance joints produced 10 residuals (3×Planar) with 6 mutually contradictory orientation constraints, causing the solver to find garbage least-squares solutions. Add early detection of App::Plane datum objects before the main geometry classification chain. Datum planes are now correctly mapped: - Vertex + DatumPlane → PointPlane → PointInPlane (1 residual) - Edge + DatumPlane → LinePlane → LineInPlane - Face/DatumPlane + DatumPlane → PlanePlane → Planar ## Summary  ## Changes  ## Related Issues  ## Checklist - [ ] Commit messages follow [conventional commits](https://www.conventionalcommits.org/) (`feat:`, `fix:`, `chore:`, `docs:`, `art:`) - [ ] Code follows project style (clang-format for C++, black for Python) - [ ] Changes are tested locally - [ ] Documentation updated (if applicable)

forbes added 1 commit 2026-02-22 18:23:46 +00:00

fix(assembly): classify datum plane references in Distance joints

Build and Test / build (pull_request) Has been cancelled

Details

a6288fd36a

When a Distance joint references a datum plane (XY_Plane, XZ_Plane,
YZ_Plane), getDistanceType() failed to recognize it because datum
plane sub-names yield an empty element type. This caused the fallback
to DistanceType::Other → BaseJointKind::Planar, which adds spurious
parallel-normal residuals that overconstrain the system.

For example, three vertex-to-datum-plane Distance joints produced
10 residuals (3×Planar) with 6 mutually contradictory orientation
constraints, causing the solver to find garbage least-squares
solutions.

Add early detection of App::Plane datum objects before the main
geometry classification chain. Datum planes are now correctly mapped:
- Vertex + DatumPlane → PointPlane → PointInPlane (1 residual)
- Edge + DatumPlane → LinePlane → LineInPlane
- Face/DatumPlane + DatumPlane → PlanePlane → Planar

forbes force-pushed fix/distance-datum-plane-classification from a6288fd36a to e5b07449d7

2026-02-22 18:25:05 +00:00

Compare

forbes merged commit cf2fc82eac into main

2026-02-22 18:25:34 +00:00

forbes deleted branch fix/distance-datum-plane-classification

2026-02-22 18:25:34 +00:00

forbes referenced this issue from a commit

2026-02-22 18:25:35 +00:00

Merge pull request 'fix(assembly): classify datum plane references in Distance joints' (#315) from fix/distance-datum-plane-classification into main

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Reference: kindred/create#315