Commit b27bcf5
Split Boolean curves at the shell's vertices, not its curves' endpoints.
FindVertsOnCurve() used the endpoints of the shell's exact curves as the
vertices to split other curves at. But an exact intersection curve can
extend past the real geometry on both sides, out to the padded bounds
that MergeCoincidentSurfaces() gives the surfaces it merges, so its
endpoints may lie at phantom positions on another surface's edge where
nothing actually happens. Splitting a curve there--when the trims
adjacent across that curve are not split there--creates T-junctions,
which triangulate into naked edges, and overlapping duplicate trim
edges with mismatched splits, which make the trim polygon fail to
assemble and leave a face missing entirely.
The real vertices of a shell are the points where its trims begin and
end, so use the trims' start and finish points instead. A curve
endpoint that the shell actually uses is such a point anyway, and the
unused tails past the last vertex no longer contribute.
Add a regression test with a model reconstructed from the recipe in
issue #1452: cuboids A (extruded down), B (up), C (up on top of B),
unioned so that their coplanar side faces merge, then cuboid D sketched
on the shared side plane and extruded away from the stack, joining only
across that plane and spanning the side faces of A, B and part of C.
Before this and the previous commit the resulting shell had a whole
side face missing; the test checks that the mesh is watertight and has
the expected volume.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UNfXectzZqpvY2c7TpGxe41 parent 906cf73 commit b27bcf5
4 files changed
Lines changed: 3533 additions & 20 deletions
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -41,26 +41,27 @@ static void FindVertsOnCurve(List<SInter> *l, const SCurve *curve, SShell *sh) { | |||
| 41 | 41 | Vector amax, amin; | |
| 42 | 42 | curve->GetAxisAlignedBounding(&amax, &amin); | |
| 43 | 43 | ||
| 44 | - for(const auto &sc : sh->curve) { | ||
| 45 | - if(!sc.isExact) continue; | ||
| 46 | - | ||
| 47 | - Vector cmax, cmin; | ||
| 48 | - sc.GetAxisAlignedBounding(&cmax, &cmin); | ||
| 49 | - | ||
| 50 | - if(Vector::BoundingBoxesDisjoint(amax, amin, cmax, cmin)) { | ||
| 51 | - // They cannot possibly intersect, no curves to generate | ||
| 52 | - continue; | ||
| 53 | - } | ||
| 54 | - | ||
| 55 | - for(int i=0; i<2; i++) { | ||
| 56 | - Vector pt = sc.exact.ctrl[ i==0 ? 0 : sc.exact.deg ]; | ||
| 57 | - double t; | ||
| 58 | - curve->exact.ClosestPointTo(pt, &t, /*must converge=*/ false); | ||
| 59 | - double d = pt.Minus(curve->exact.PointAt(t)).Magnitude(); | ||
| 60 | - if((t>LENGTH_EPS) && (t<(1.0-LENGTH_EPS)) && (d < LENGTH_EPS)) { | ||
| 61 | - SInter inter; | ||
| 62 | - inter.p = pt; | ||
| 63 | - l->Add(&inter); | ||
| 44 | + // The vertices of the shell are the endpoints of its trims, not the | ||
| 45 | + // endpoints of its curves: an exact intersection curve may extend past | ||
| 46 | + // the real geometry on both sides (e.g. out to the padded bounds of a | ||
| 47 | + // surface that got enlarged by SShell::MergeCoincidentSurfaces()), and | ||
| 48 | + // splitting some other curve at such a phantom point--which is not a | ||
| 49 | + // vertex of the trims adjacent across that other curve--produces | ||
| 50 | + // T-junctions and naked edges in the triangulated shell (issue #1452). | ||
| 51 | + for(const SSurface &ss : sh->surface) { | ||
| 52 | + for(const STrimBy &stb : ss.trim) { | ||
| 53 | + for(int i = 0; i < 2; i++) { | ||
| 54 | + Vector pt = (i == 0) ? stb.start : stb.finish; | ||
| 55 | + if(pt.OutsideAndNotOn(amax, amin)) continue; | ||
| 56 | + | ||
| 57 | + double t; | ||
| 58 | + curve->exact.ClosestPointTo(pt, &t, /*mustConverge=*/false); | ||
| 59 | + double d = pt.Minus(curve->exact.PointAt(t)).Magnitude(); | ||
| 60 | + if((t > LENGTH_EPS) && (t < (1.0 - LENGTH_EPS)) && (d < LENGTH_EPS)) { | ||
| 61 | + SInter inter = {}; | ||
| 62 | + inter.p = pt; | ||
| 63 | + l->Add(&inter); | ||
| 64 | + } | ||
| 64 | 65 | } | |
| 65 | 66 | } | |
| 66 | 67 | } | |
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -63,6 +63,7 @@ set(testsuite_SOURCES | |||
| 63 | 63 | request/line_segment/test.cpp | |
| 64 | 64 | request/ttf_text/test.cpp | |
| 65 | 65 | request/workplane/test.cpp | |
| 66 | + group/boolean_coplanar_union/test.cpp | ||
| 66 | 67 | group/boolean_knife_edge/test.cpp | |
| 67 | 68 | group/boolean_tangent_edge/test.cpp | |
| 68 | 69 | group/boolean_tangent_fillet/test.cpp | |
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