Replaces naive ReplaceEntity approach with NX's proper
ReplaceFeatureBuilder API. This mirrors the interactive
right-click → Replace Feature workflow:
- SelectFeature: old sketch to replace
- ReplacementFeature: new sketch taking over
- DoAutomaticGeomMatch: auto-maps curves
- DeleteOriginalFeature: removes old after remap
- Fallback: manual delete if builder fails
All downstream features (extrude, trim) automatically
re-reference the new sketch.
Complete rewrite of triangulation engine:
- Regular hexagonal-packed vertex grid (equilateral triangles)
- Density-adaptive refinement: denser near holes, coarser in open areas
- Boundary-conforming vertices along frame edge and hole keepouts
- Delaunay on point set + clip to valid region (inside frame, outside keepouts)
- Result: proper isogrid layout, 87 pockets from 234 triangles
- 553 NX entities, min fillet 4.89mm, mass 2770g
- No more dependency on Shewchuk Triangle library (scipy.spatial.Delaunay)
- Switched to uniform triangulation (no density-adaptive refinement for
initial pass — saves that for stress-informed iterations)
- s_min=45mm, s_max=55mm (was 12/35) — larger triangles fit 6mm fillets
- Boss keepout circles: 12 segments (was 32) — less boundary clutter
- Fillet must be >= 80% of r_f at every corner or pocket is skipped
- Result: 75 pockets, 481 NX entities, min fillet 4.85mm, mass 4066g
- adaptive_density=True param enables density refinement for future stress iterations
- Default r_f raised from 1.5mm to 6mm (machining constraint)
- Default min_pocket_radius raised to 6mm
- Pockets that can't fit r_f at any corner (within 80% tolerance) are
skipped entirely — left solid for more stiffness in tight areas
- Result: 26 pockets (was 432), 187 NX entities (was 13,061)
- Min fillet radius: 4.88mm, all >= 4.8mm (80% of 6mm)
- Mass: 4,601g (was 3,480g — more solid = heavier but manufacturable)
Model curves (part.Curves.CreateLine) are SmartObjects that can't be added
to a sketch via AddGeometry. Switch to SketchLineBuilder which creates
native sketch geometry directly (SetStartPoint/SetEndPoint/Commit).
