v5.1.2

pySMESH 5.1.2

v5.1.1

pySMESH 5.1.1

pySMESH 5.1.0

5.1.0 adds NETGEN: free tetrahedra and triangles, a remesher for triangle surfaces, and
boundary layers with a tetrahedral core. It also completes the boundary layers on the SMESH
algorithms. No public name is removed. Calls that ran on 5.0.0 give the same results, except
where 5.0.0 returned a wrong result in silence (see "Fixes and new refusals").

NETGEN

• netgen 6.2.2101 with SALOME's netgen62ForSalome.patch and the OCCT 8 port, and
  NETGENPlugin V9_16_0. Both are built from source into _core.pyd, with zlib 1.3.2. They
  add no DLL to the wheel.
• Algorithms: Netgen1D2D3D (a whole solid), Netgen3D (tetrahedra from the mesh of the
  faces), Netgen1D2D (faces from the edges up), Netgen2D (faces on existing edges),
  NetgenRemesher2D (a triangle surface with no CAD behind it).
• Hypotheses: NetgenParameters, NetgenParameters2D, NetgenSimpleParameters2D,
  NetgenSimpleParameters3D, NetgenRemesherParameters2D, and the Fineness presets. Local
  sizes are given per sub-shape. A field that a fineness preset controls is accepted only with
  Fineness.USER_DEFINED.
• Mixed meshes: NETGEN reuses the nodes of edges and faces that another algorithm meshed,
  so Quadrangle2D faces and NETGEN tetrahedra share one conformal mesh.
• Embedding: a NETGEN compute writes nothing to the console, writes no file, never changes
  the working directory and leaves no temporary file. One process-wide lock serializes NETGEN
  calls, so two threads can mesh at once. The mesh is identical at 1, 4 and 16 threads. A
  cancel lands within 5 s and the mesher can compute again.
• Plugin defects fixed: a face's local size went to the face before it; an edge's local
  size stopped short of its last vertex; the chordal error did nothing on curved faces (OCCT 8
  returns a stale curvature); parallel debug text corrupted the heap; the remesher crashed
  without parameters, overflowed its stack on a NaN size, and left part of a new mesh after a
  cancel. The upstream fix e1d71a78 (a crash at process exit) is backported. The other
  upstream netgen fixes after 2101 were reviewed; none applies to this build.

Boundary layers

• NETGEN with layers: ViscousLayers on Netgen3D and Netgen1D2D3D (prisms or
  hexahedra on the chosen walls, tetrahedra inside), ViscousLayers2D on Netgen2D and
  Netgen1D2D, and ViscousLayerBuilder with a NETGEN inner mesh.
• CompositeHexa3D builds ViscousLayers, and PolygonPerFace2D builds
  ViscousLayers2D. Both were refused in 5.0.0.
• Several ViscousLayers on one solid (a thickness per face set). unassign now detaches
  exactly the hypothesis it is given.
• A sweep carries the 2-D layers of its source face through every level.
• Cartesian layers that are too thick name the largest thickness that works.
• A layer stack cut short in a narrow gap reports a warning in ComputeReport.warnings.

Prism3D

• Prism3D sweeps through a side face whose horizontal side is split into several edges,
  when the projection gives every split point a node and every edge the segment count of its
  own hypothesis. Otherwise it refuses, names the edges and the counts, and gives the way out.

Fixes and new refusals

Each one raises PysmeshError with the reason. In 5.0.0 each case returned a wrong result in
silence.

• A compute that leaves a sub-shape unmeshed because its algorithm misses a hypothesis. SMESH
  reports success there; pySMESH now raises and names the sub-shape.
• Cartesian layers whose offset is not a valid solid, or whose cells fold over. 5.0.0 meshed
  them with inverted cells or nodes outside the shape.
• Layer face sets that an algorithm cannot read, a second layer hypothesis on an algorithm
  that reads one, and 2-D layers on a face that a solid's algorithm or a sweep would drop.
• A compute error built from a std::string lost its first 7 characters.
• After a cancel, a mesher could not compute again.

Wheel

	5.0.0	5.1.0
Wheel (cp313)	39 991 976 bytes (38.1 MiB)	41 501 951 bytes (39.6 MiB)
Bundled DLLs	52	52

Known limits

• netgen 2101 fails on a unit sphere at Fineness.COARSE with max size 0.866. It fails with
  netgen's reason.
• Cartesian layers are not repeatable run to run on some shapes, as in 5.0.0.
• netgen's own boundary layers are not used: layers come from SMESH's ViscousLayers.

pySMESH 5.0.0

5.0.0 moves both native kernels to new releases and fixes every pySMESH defect found in a full
sweep of 4.2.2. The public API only grows: no name is removed. The major number marks
changed results and new refusals. Code that ran on 4.2.2 can now get a different mesh,
a different measure, or an exception where 4.2.2 returned a bad result in silence.

Native kernels

• SALOME SMESH, KERNEL and GEOMUtils V9_9_0 → V9_16_0. Four years of upstream
  algorithm work, including the rewritten Cartesian mesher. KERNEL's basics now come from
  salome_bootstrap V9_16_0. Mefisto2D stays public: upstream deleted it in 2022, so
  its V9_9_0 sources are carried forward unchanged.
• OCCT 8.0.0 → 8.0.1, built from source by ci/build_occt.py, with only the toolkits
  that _core needs. Three OCCT patches:
  • the ruled loft history through four or more closed single-edge sections;
  • a native crash in chamfer;
  • a native crash in pipe.
• SALOME patches: 36 on SMESH, KERNEL and GEOM. Among the fixes: the TABLE and
  EXPRESSION distributions, the Adaptive1D crash, its deflection and size bounds, and the
  Cartesian cancel. PROVENANCE.md lists every patch.

Wheel

	4.2.2	5.0.0
Wheel (cp313)	43 345 198 bytes (41.3 MiB)	39 991 806 bytes (38.1 MiB)
Bundled DLLs	75	52

NumPy is still the only runtime dependency. OCCT, Boost and VTK stay private to the wheel.

Changed results

If your code compares against stored values from 4.x, expect these to move.

• TABLE and EXPRESSION distributions place their nodes at the positions the function
  defines. 4.x used an absolute bisection tolerance and a single 20-point Gauss rule, so
  steep tables and expressions were off.
• Adaptive1D no longer crashes on a shape with faces. Every edge now meets its
  deflection, [min_size, max_size] and the factor 2 between neighbours. Segment counts
  change only on the edges that broke a rule before.
• Measures (the default volume, area and length) are adaptive at relative precision
  1e-6, as Session.mass_properties. 4.x gave a lofted wing's volume 20 % low.
• Bounding boxes are the geometry's box. They are no longer grown by the shape
  tolerance, and a B-spline box bounds the curve, not its poles.
• Mefisto2D honours MaxElementArea. In 4.x the bound had no effect.
• The medial axis samples straight edges with at least 10 points (SMESH 9.16).
• A SMESH warning no longer fails the compute. It is reported in
  ComputeReport.warnings.

New refusals

Each one raises PysmeshError with the reason and the offending ids. In 4.x each case
returned a result that was wrong, or crashed the process.

• A boolean whose result is empty or not watertight.
• An inside-out solid on import. Pass inside_out="reverse" to load_brep or
  Session.add_brep to repair it instead.
• sew(make_solid=True) when no solid can be made.
• A swept or lofted solid that crosses itself, including sections that meet at one point.
• A solid loft with a non-planar end section, and a loft with a slit inside.
• A NaN or infinite argument to a geometry operation. Before, it reached OCCT and could
  crash the process.
• An assignment that makes the model ambiguous (SMESH's HYP_CONCURRENT). assign raises
  and undoes the assignment.
• A hypothesis value that SMESH refuses.
• Viscous layers under an algorithm that does not build them. Hexa3D,
  PolyhedronPerSolid3D and Cartesian3D build 3-D layers. CompositeHexa3D with layers is
  refused.
• A layer stack with total_thickness <= 0, layer_count < 1 or stretch_factor < 1, at
  construction. stretch_factor = 1 (equal layers) is now accepted.
• Prism3D on a composite horizontal side. The message names the way out. 4.x threw
  Standard_NotImplemented: Adaptor3d_Surface::EvalD0 there.

New API

• Algorithms and hypotheses from SMESH 9.16: SegmentAroundVertex0D, UseExisting1D,
  UseExisting2D, PropagOfDistribution, LayerDistribution2D, LengthFromEdges,
  BlockRenumber, NotConformAllowed.
• New fields:
  • reversed_edges on NumberOfSegments, Arithmetic1D, StartEndLength, Geometric1D
    and FixedPoints1D;
  • Distribution.BETA_LAW with beta;
  • enforced_vertices and enforced_points on QuadrangleParams;
  • explicit grid coordinates, fixed_point, axis_directions, use_quanta / quanta and
    threshold_for_internal_faces on CartesianParameters3D.
• Viscous layers: ViscousLayerBuilder, with Mesher.shrink_geometry and
  Mesher.add_layers (shrink the geometry, mesh it, then add the layers), and
  first_layer_thickness(total_thickness, stretch_factor, layer_count).
• Mesh operations and controls: Mesher.make_boundary_mesh with BoundaryDimension,
  Mesher.ray_volumes returning RayVolumeHits, split_volumes(avoid_over_constrained=...),
  add_nodes / add_elements bound to a sub-shape (on=, parameters=), and the
  Warping3D and ScaledJacobian quality controls.
• Session:
  • entities(kind, distinct=True) and alias_groups(kind);
  • export_handoff(allow_aliases=True), with Handoff.solid_ids_of, face_ids_of,
    edge_ids_of and vertex_ids_of;
  • Session.write_step, with face names keyed by session id;
  • a closed loft: name the first section again as the last;
  • HistoryDelta.warnings.
• Reporting: ComputeReport.warnings (ComputeWarning: kind, ordinal, algorithm,
  text).
• Misc: pysmesh.__version__. read_iges takes the file content as bytes, or a path.

Migration

• read_iges(path=...) is now read_iges(data_or_path=...). A positional call is
  unchanged.
• If you caught the exception that a SMESH warning raised, read ComputeReport.warnings
  instead.
• If you import solids of unknown orientation, pass inside_out="reverse".
• If you assign hypotheses on overlapping sub-shapes, assign on the shared sub-shape first:
  it takes priority over those around it.
• Re-baseline stored meshes and measures that use TABLE or EXPRESSION distributions,
  Adaptive1D, Mefisto2D with MaxElementArea, bounding boxes, or default measures.

Known limits

• Prism3D on a composite horizontal side is refused, not meshed.
• Viscous layers with CompositeHexa3D are refused.
• Cartesian viscous layers thicker than the shape allows are refused with the reason.
• OCCT pads B-spline and Bezier boxes by 1e-7. A strict entities_in_box query at a
  spline's exact extent misses by that amount.
• There is no free tetrahedral volume mesher. NETGEN is planned.

v4.2.2

pySMESH 4.2.2

v4.2.1

pySMESH 4.2.1

v4.2.0

pySMESH 4.2.0

v4.1.2

pySMESH 4.1.2

v4.1.1

offsets and extraction

v4.1.0

edge geometry and entity clearance