1b-agent/OneCAD-Simulation
1
0 Fork 0
forked from 1b-agent/fieldcraft-upstream
Code Pull Requests Activity

Constrained Delaunay tetrahedralization (boundary recovery) and mesh.tet.generate (M2) (#29)

Browse Source 
* predicates: LNC points, generic insphere and its perturbed form (Diazzi et al. 2023 §4.3)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* mesh: constrained Delaunay tetrahedralization (segment recovery with LNC Steiner points, gift-wrapping facet recovery, labelling)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* cdt: rounding repair, mesh.tet.generate, corpus CDT column; review cleanups (shared perturbation rule, one facet scan, cached coordinates, worklist segment recovery)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* mesh.tet.generate is ready in the catalogue; corpus table with the CDT column

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

---------

Co-authored-by: jyviko <2501648+jyviko@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
Irakli KourtisClaude Opus 5.5jyviko
 authored and GitHub committed 2026-10-13 18:37:09 -04:00
1 parent e688f6f934
commit aa68bbbcdf
24 files changed
+2876 -56
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

docs/architecture.md
+3 -2
View File
@@ -61,8 +61,9 @@ Rules beyond the layer order:
position.
3. **Tetrahedral meshing.** Bowyer–Watson Delaunay on Shewchuk's adaptive predicates (symbolic
perturbation for degeneracies), boundary recovery by the robust constrained Delaunay method of
Diazzi et al. 2023 (implicit Steiner points on indirect predicates, gift-wrapping fallback), so
every boundary triangle and its B-rep face tag survives. Then constrained Delaunay refinement to a
Diazzi et al. 2023 (implicit Steiner points on indirect predicates, gift-wrapping facet
recovery; `modelcraft-mesh::cdt`, command `mesh.tet.generate`), so every boundary triangle and
its B-rep face tag survives. Then constrained Delaunay refinement to a
size field, ODT smoothing interleaved as in Tournois et al. 2009, and the Klingner–Shewchuk 2007
improvement schedule against slivers.
4. **Hexahedral meshing (the core).** Octree/grid dual all-hex first, the one family that meshes
docs/features.md
+1 -1
View File
@@ -27,7 +27,7 @@ shown greyed with the roadmap milestone that brings them (ROADMAP.md).
| Size | Global Size — One element size for the whole part | coming soon (M2) | |
| Size | Seed Edges — Element counts, sizes and bias per edge and face | coming soon (M2) | |
| Size | Curvature — Refine by curvature and proximity | coming soon (M2) | |
| Tet | Tet Mesh — Delaunay tetrahedral mesh of a body, boundary recovered and refined | coming soon (M2) | |
| Tet | Tet Mesh — Constrained Delaunay tet mesh of a body: every boundary triangle kept, faces tagged (refinement comes next) | ready | `mesh.tet.generate` |
| Tet | Quadratic — Second-order elements with mid-side nodes on the geometry | coming soon (M2) | |
| Tet | Delaunay Points — Delaunay tetrahedralization of a point list (debugging aid) | ready | `mesh.delaunay.points` |
| Structured Hex | Quad Faces — All-quad meshes of faces on shared edge nodes | coming soon (M5) | |
docs/meshing/corpus.md
+23 -23
View File
@@ -8,29 +8,29 @@ clock on the machine that ran it; every other column is deterministic.
## Results
| part | categories | bodies | faces | triangles | tol. mm | build ms | enclosed mm³ | SolidCraft mm³ | rel. diff | exact mm³ | boundary | genus | feature edges | check ms |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| bent-tube | sweepable, thin-wall, genus | 1 | 18 | 4296 | 0.121 | 432 | 4213.1 | 4159.4 | 1.3e-2 | 4159.8 | ok, 2148 vertices | 1 | 268 | 11.4 |
| bolted-assembly | assembly, blocky | 3 | 22 | 284 | 0.117 | 57 | 33004.7 | 32999.0 | 1.7e-4 | 32998.9 | ok, 144 vertices | 0, 1, 1 | 104 | 0.7 |
| cross-cylinders | boolean, sharp | 1 | 10 | 1395 | 0.087 | 7548 | 32197.4 | 32357.8 | -5.0e-3 | 32365.8 | error: Cross: invalid boundary surface: 28 defects; triangles 142 and 184 are oriented inconsistently across edge 0–396 at (-15.488656021315903, 4.577998041166734, 7.853092194999726); triangles 184 and 239 are oriented inconsistently across edge 0–554 at (-18.75000000000002, 5.634596901641276, 7.632255089815496); edge 103–108 at (-0.16007784063084018, 0.03984236936862052, 9.998639270596865) is shared by 3 triangles; … | | | |
| filleted-bracket | fillet, genus, sweepable | 1 | 13 | 540 | 0.088 | 388 | 32162.3 | 32145.0 | 5.4e-4 | 32144.8 | ok, 268 vertices | 2 | 135 | 1.4 |
| i-beam | sweepable, thin-wall | 1 | 14 | 44 | 0.208 | 4 | 61600.0 | 61600.0 | 0.0e0 | 61600.0 | ok, 24 vertices | 0 | 36 | 0.1 |
| loft-transition | organic | 1 | 6 | 292 | 0.075 | 54 | 56390.2 | 56450.6 | -1.1e-3 | – | ok, 148 vertices | 0 | 40 | 0.7 |
| perforated-plate | genus, thin-wall, sweepable | 1 | 54 | 1644 | 0.144 | 270 | 26822.2 | 26764.6 | 2.2e-3 | 26764.2 | ok, 776 vertices | 24 | 828 | 4.9 |
| pinhole-block | small-feature, genus | 1 | 38 | 4044 | 0.073 | 206 | 49919.4 | 49909.6 | 2.0e-4 | 49909.5 | ok, 1992 vertices | 16 | 1548 | 12.9 |
| rounded-box | fillet | 1 | 26 | 2540 | 0.054 | 149 | 23325.7 | 23340.5 | -6.3e-4 | 23340.8 | ok, 1272 vertices | 0 | 216 | 6.7 |
| shallow-groove | near-tangent, boolean | 1 | 8 | 62 | 0.075 | 11 | 47795.2 | 47782.3 | 2.7e-4 | 47781.5 | ok, 33 vertices | 0 | 24 | 0.1 |
| sharp-wedge | sharp, thin-wall, sweepable | 1 | 5 | 8 | 0.083 | 2 | 3200.0 | 3200.0 | 0.0e0 | 3200.0 | ok, 6 vertices | 0 | 9 | 0.0 |
| sphere-on-plate | near-tangent, boolean | 1 | 12 | 2826 | 0.098 | 682 | 69353.3 | 69509.0 | -2.2e-3 | 69509.7 | ok, 1415 vertices | 0 | 124 | 6.1 |
| spline-vase | organic | 1 | 11 | 3890 | 0.106 | 217 | 94891.2 | 94948.5 | -6.0e-4 | – | ok, 1947 vertices | 0 | 243 | 8.9 |
| stepped-block | blocky, sharp | 1 | 14 | 96 | 0.078 | 35 | 47000.0 | 47000.0 | 0.0e0 | 47000.0 | ok, 48 vertices | 1 | 60 | 0.4 |
| thin-ribs | thin-wall, blocky | 1 | 26 | 92 | 0.119 | 69 | 32000.0 | 32000.0 | -4.5e-16 | 32000.0 | ok, 48 vertices | 0 | 72 | 0.5 |
| thin-wall-enclosure | thin-wall, blocky | 1 | 11 | 36 | 0.108 | 9 | 15564.0 | 15564.0 | 0.0e0 | 15564.0 | ok, 20 vertices | 0 | 28 | 0.1 |
| analytic-sphere | analytic | 1 | 6 | 2784 | 0.069 | 245 | 33353.4 | 33507.9 | -4.6e-3 | 33510.3 | ok, 1394 vertices | 0 | 96 | 6.1 |
| analytic-torus | analytic, genus | 1 | 6 | 7230 | 0.109 | 334 | 37644.1 | 37893.7 | -6.6e-3 | 37899.3 | ok, 3615 vertices | 1 | 180 | 16.1 |
| analytic-cylinder | analytic, sweepable | 1 | 4 | 1004 | 0.049 | 25 | 12533.1 | 12564.7 | -2.5e-3 | 12566.4 | ok, 504 vertices | 0 | 106 | 2.7 |
| analytic-pipe | analytic, genus, sweepable | 1 | 6 | 1448 | 0.104 | 44 | 94150.9 | 94238.0 | -9.3e-4 | 94247.8 | ok, 724 vertices | 1 | 220 | 3.9 |
| analytic-plate-hole | analytic, genus, sweepable | 1 | 8 | 112 | 0.224 | 11 | 98449.1 | 98429.5 | 2.0e-4 | 98429.2 | ok, 56 vertices | 1 | 62 | 0.4 |
| part | categories | bodies | faces | triangles | tol. mm | build ms | enclosed mm³ | SolidCraft mm³ | rel. diff | exact mm³ | boundary | genus | feature edges | check ms | CDT tets | Steiner | cavities | tet gate | CDT ms |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| bent-tube | sweepable, thin-wall, genus | 1 | 18 | 4296 | 0.121 | 435 | 4213.1 | 4159.4 | 1.3e-2 | 4159.8 | ok, 2148 vertices | 1 | 268 | 10.9 | 15550 | 2338 | 0 | pass | 550 |
| bolted-assembly | assembly, blocky | 3 | 22 | 284 | 0.117 | 54 | 33004.7 | 32999.0 | 1.7e-4 | 32998.9 | ok, 144 vertices | 0, 1, 1 | 104 | 0.7 | 690 | 181 | 0 | pass | 31 |
| cross-cylinders | boolean, sharp | 1 | 10 | 1395 | 0.087 | 7682 | 32197.4 | 32357.8 | -5.0e-3 | 32365.8 | error: Cross: invalid boundary surface: 28 defects; triangles 142 and 184 are oriented inconsistently across edge 0–396 at (-15.488656021315903, 4.577998041166734, 7.853092194999726); triangles 184 and 239 are oriented inconsistently across edge 0–554 at (-18.75000000000002, 5.634596901641276, 7.632255089815496); edge 103–108 at (-0.16007784063084018, 0.03984236936862052, 9.998639270596865) is shared by 3 triangles; … | | | | error: Cross: invalid boundary surface: 28 defects; triangles 142 and 184 are oriented inconsistently across edge 0–396 at (-15.488656021315903, 4.577998041166734, 7.853092194999726); triangles 184 and 239 are oriented inconsistently across edge 0–554 at (-18.75000000000002, 5.634596901641276, 7.632255089815496); edge 103–108 at (-0.16007784063084018, 0.03984236936862052, 9.998639270596865) is shared by 3 triangles; … | | | | |
| filleted-bracket | fillet, genus, sweepable | 1 | 13 | 540 | 0.088 | 381 | 32162.3 | 32145.0 | 5.4e-4 | 32144.8 | ok, 268 vertices | 2 | 135 | 1.4 | 5582 | 1613 | 0 | pass | 187 |
| i-beam | sweepable, thin-wall | 1 | 14 | 44 | 0.208 | 4 | 61600.0 | 61600.0 | 0.0e0 | 61600.0 | ok, 24 vertices | 0 | 36 | 0.1 | 94 | 24 | 0 | pass | 3 |
| loft-transition | organic | 1 | 6 | 292 | 0.075 | 55 | 56390.2 | 56450.6 | -1.1e-3 | – | ok, 148 vertices | 0 | 40 | 0.7 | 1329 | 256 | 1 | pass | 33 |
| perforated-plate | genus, thin-wall, sweepable | 1 | 54 | 1644 | 0.144 | 265 | 26822.2 | 26764.6 | 2.2e-3 | 26764.2 | ok, 776 vertices | 24 | 828 | 4.6 | 33611 | 9798 | 0 | pass | 1195 |
| pinhole-block | small-feature, genus | 1 | 38 | 4044 | 0.073 | 202 | 49919.4 | 49909.6 | 2.0e-4 | 49909.5 | ok, 1992 vertices | 16 | 1548 | 12.4 | 96411 | 30221 | 0 | pass | 4408 |
| rounded-box | fillet | 1 | 26 | 2540 | 0.054 | 156 | 23325.7 | 23340.5 | -6.3e-4 | 23340.8 | ok, 1272 vertices | 0 | 216 | 6.3 | 11666 | 1913 | 0 | pass | 371 |
| shallow-groove | near-tangent, boolean | 1 | 8 | 62 | 0.075 | 11 | 47795.2 | 47782.3 | 2.7e-4 | 47781.5 | ok, 33 vertices | 0 | 24 | 0.2 | 267 | 87 | 0 | pass | 11 |
| sharp-wedge | sharp, thin-wall, sweepable | 1 | 5 | 8 | 0.083 | 2 | 3200.0 | 3200.0 | 0.0e0 | 3200.0 | ok, 6 vertices | 0 | 9 | 0.0 | 11 | 3 | 0 | pass | 0 |
| sphere-on-plate | near-tangent, boolean | 1 | 12 | 2826 | 0.098 | 703 | 69353.3 | 69509.0 | -2.2e-3 | 69509.7 | ok, 1415 vertices | 0 | 124 | 5.7 | 4898 | 309 | 9 | pass | 214 |
| spline-vase | organic | 1 | 11 | 3890 | 0.106 | 230 | 94891.2 | 94948.5 | -6.0e-4 | – | ok, 1947 vertices | 0 | 243 | 8.5 | 12461 | 1512 | 0 | pass | 419 |
| stepped-block | blocky, sharp | 1 | 14 | 96 | 0.078 | 30 | 47000.0 | 47000.0 | 0.0e0 | 47000.0 | ok, 48 vertices | 1 | 60 | 0.4 | 223 | 41 | 0 | pass | 6 |
| thin-ribs | thin-wall, blocky | 1 | 26 | 92 | 0.119 | 62 | 32000.0 | 32000.0 | -4.5e-16 | 32000.0 | ok, 48 vertices | 0 | 72 | 0.5 | 171 | 33 | 0 | pass | 6 |
| thin-wall-enclosure | thin-wall, blocky | 1 | 11 | 36 | 0.108 | 8 | 15564.0 | 15564.0 | 0.0e0 | 15564.0 | ok, 20 vertices | 0 | 28 | 0.1 | 191 | 47 | 2 | pass | 5 |
| analytic-sphere | analytic | 1 | 6 | 2784 | 0.069 | 263 | 33353.4 | 33507.9 | -4.6e-3 | 33510.3 | ok, 1394 vertices | 0 | 96 | 5.8 | 4211 | 58 | 0 | pass | 258 |
| analytic-torus | analytic, genus | 1 | 6 | 7230 | 0.109 | 345 | 37644.1 | 37893.7 | -6.6e-3 | 37899.3 | ok, 3615 vertices | 1 | 180 | 15.4 | 19790 | 466 | 0 | pass | 717 |
| analytic-cylinder | analytic, sweepable | 1 | 4 | 1004 | 0.049 | 25 | 12533.1 | 12564.7 | -2.5e-3 | 12566.4 | ok, 504 vertices | 0 | 106 | 2.7 | 7437 | 1568 | 0 | pass | 259 |
| analytic-pipe | analytic, genus, sweepable | 1 | 6 | 1448 | 0.104 | 43 | 94150.9 | 94238.0 | -9.3e-4 | 94247.8 | ok, 724 vertices | 1 | 220 | 3.7 | 6238 | 1340 | 0 | pass | 264 |
| analytic-plate-hole | analytic, genus, sweepable | 1 | 8 | 112 | 0.224 | 11 | 98449.1 | 98429.5 | 2.0e-4 | 98429.2 | ok, 56 vertices | 1 | 62 | 0.4 | 1868 | 543 | 0 | pass | 53 |
## Categories
docs/meshing/literature.md
+15
View File
@@ -238,6 +238,21 @@ Delaunay methods with Voronoi/ODT improvement, then (2) all-hex and hex-dominant
- **Complexity.** High: about 8–12k lines of Rust including the predicate generator. It is the single most valuable
investment in the tet pipeline.
- **Code.** `MarcoAttene/CDT` is **GPL, or LGPL by build option** (README): FORBIDDEN.
- **Implemented** in `modelcraft-mesh::cdt` from the paper only, with these choices:
- Steiner points are LNC points (§4.3) on the original segment, `a + t (b − a)` with `t` a double; the in-sphere test
on them is exact (interval filter, then exact dyadic integers) and perturbed with the same lexicographic lift as
the Delaunay step, so Bowyer–Watson insertion of Steiner points stays consistent with it.
- Facet recovery uses the modified gift-wrapping (§4.4) for every cavity, not only after Si's cavity expansion
fails: it is the always-correct path, and Si's expansion is a speed-up. Condition (ii) is an exact
proper-intersection test of closed simplices (separating plane through three of the vertices, then recursion
into the contact plane), which handles the coplanar configurations of CAD tessellations; recovered facets inside
a cavity stay constraints.
- Reference points (§3.3) are searched among the tetrahedra whose boxes meet the missing subsegment's box (they
contain the tetrahedra the subsegment crosses); on the corpus this picks the same point as searching the whole
diametral ball.
- Rounding (§5.1): a Steiner point whose rounding leaves an incident tetrahedron non-positive tries the doubles
within two ulps per coordinate, nearest first; the flip-based improvement of §5.1 is not implemented. All 20
valid corpus parts pass the validity gate after rounding.
**A2.4 Diazzi and Attene 2021, convex polyhedral meshing.** **Verdict: reference.**
- **Citation.** L. Diazzi, M. Attene. *Convex polyhedral meshing for robust solid modeling.* ACM TOG 40(6):259, 2021.