A merged face on several surfaces (a sliver absorbed into its neighbour)
had no exact surface, so the projection target fell back to its
triangles: flat curvature probes gave fewer divisions round the boss and
the enclosure base's symmetric mesh dropped from 0.70 to 0.51 once its
absorbs reached the cells. The target now projects a point of such a
face onto the exact surface of the B-rep piece it is on, trimmed to that
piece (Tessellation::with_pieces, Shape::tessellate_pieces); node
relaxation slides on it the same way.
Test from commands: the enclosure base's four slivers absorbed, meshed
whole and by symmetry, the absorbs kept in every cell.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
With "transition": "pyramid" (the default; "tie" keeps the old join) a tet
cell is meshed after the hex cells, with a pyramid on every hex face of its
cuts and its tetrahedra on the pyramids' sides: one conforming mesh, no tie.
Where it cannot be built the cell says why (no_pyramids) and is tied. The
apex height is 0.4 of the quad's edge, so pyramids on faces meeting at a
right angle do not cross.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
transition::pyramid_surface puts a pyramid on every hex interface quad and
builds the tet region's surface closed by the pyramid sides, re-stitching the
neighbouring faces to the hex rim nodes. QualityOptions::frozen_faces keeps
those sides exactly (TetComplex refuses changes that remove or add a frozen
face; their vertices are corners), and apex_points checks the result.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The owner's direction: bad nodes move to better places, the nodes within a reach follow by
the graph Laplacian's harmonic extension, edges held, nothing outside the reach moves.
mesh.node.relax strong mode takes below and reach and reports each round.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The extrude/revolve cross-section took both ends of every B-rep edge as curve ends. A closed
edge without a vertex on it (a hole's rim after geometry.faces.merge of its halves) starts
wherever its chain was picked up, the old seam vertex, so that point stayed a curve end and a
node column stayed on the merged boundary. Only open edges' ends (and the B-rep vertices) are
curve ends now; the layout and interval assignment place the rim's nodes.
The hex test runs on a square plate and asserts the seams carry exactly as many nodes as the
same lines turned a quarter round the hole (10 and 10; before 5 and 10): the corner layout
puts arc-midpoint nodes there by symmetry, so 0 is not the right target.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A five-node pyramid, the conforming transition between a hexahedron's face
and tetrahedra: Bedrosian's rational shape functions with a collapsed (Duffy)
Gauss rule, a certified Jacobian on the base square with exact volume, a
scaled Jacobian, C3D5 / CPYRAM / LS-DYNA degenerate solid, VTK_PYRAMID and
the binary mesh code 13. A distorted hex8-pyramid5-tet4 transition mesh
passes the patch test and uniaxial tension exactly.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A patch of quads already meshed on a face of the body (a neighbour's mesh)
is matched to the block faces on it: block vertices to its nodes (its
singular nodes first, then along its grid lines), block edges along its
grid lines, faces filled quad by quad. Those faces take the patch's
divisions and nodes, held through smoothing. mesh.hex.project takes
"fixed": [face names] and builds the patch from other bodies' meshes.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
project_trimmed accepted the exact surface's point up to a fifth of the
nearest triangle's median edge off the face: on a tall fillet piece
(triangles 30 mm long) that let a point on a sibling piece of the same
cylinder count as on it, so every quad round the corner took the first
piece's name. The slack is now the triangle's own chordal gap to the
surface, doubled.
A face narrower than the elements (the sliver a corner boss leaves of the
inner fillet) gets one row of the quads it runs through, from the
neighbour with the most quads left. Tessellation::nearest_face finds the
face nearest a point.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The compass search after the sweeps moves the nodes of the worst elements one at a time, each to
its own best place. Since it lifts every element below 0.7 (#462) it moves many surface nodes,
and a column of them on a face ends at scattered places: the enclosure base's inner walls showed
zigzag element lines in a column next to each corner, full height. A last pass now moves each
surface node back toward the mean of its neighbours on the surface, as far as no element round
it falls below the lower of its own value and the mesh's smallest after the search, so the lines
straighten and the mesh's worst element is no worse.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Projecting a point onto one B-rep face searched one box tree over every triangle of the
boundary, skipping the other faces' triangles: when other faces lie nearer the point than the
target face, it walked most of the tree before reaching a triangle it could use. Smoothing a
projected mesh projects every boundary node many times, onto every face of its target group,
so the Pi 5 enclosure base spent 95 % of its 11 minutes there. Each face (and each face pair's
curve) now has a tree of its own: the same nearest triangle, found among its own boxes only.
Ties between triangles at the same distance went to whichever the tree's walk met first; they
now go to the lowest triangle, so the result no longer depends on how a tree is built. With
that rule the per-face trees and the whole-boundary tree give bitwise the same mesh.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
#462 visited nodes by a mirror-invariant key (distance from the centroid). On the cup with a
handle that order sweeps ring by ring round the axis and converges worse in its 100 sweeps: the
refined cup fell to a scaled Jacobian of 0.481 (needs 0.5, #440). In the lattice's own order
it holds, and the order gained the enclosure base little (its corners differ by 0.02 either
way), so it goes; the compass search's lift to 0.7 stays.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The compass search after the sweeps only lifted elements below 0.5 (the quality floor), so a
mesh whose worst elements sat just above it stayed there: every corner of an enclosure base
stopped at a scaled Jacobian of 0.50-0.52 where its walls meet the corner bosses. It now lifts
every element below 0.7, never lowering another below the lower of its own value and 0.5.
The sweeps and the search are Gauss-Seidel, so the node order shaped the result and mirror
image corners smoothed differently. Nodes are now visited by a key that a mirror or a quarter
turn about the nodes' centroid keeps (distance from it, then the sorted offsets along the
axes). What spread is left between mirrored corners (0.686 vs 0.702 on the test base) is most likely the projection onto the body's
tessellation, which the kernel does not make mirror symmetric (not yet proven).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The crank ends at 8, 16, 20 and 22 mm, so no one-to-one sweep takes it.
The sweep met one of those caps as a linking face and reported "linking
face has no top side". A plane parallel to the source that only part of a
ring reaches is now named as what it is, with extrude pointed to. The arm's
profile alone sweeps as well as extrude does.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A smooth loop (straight sides running tangent into arcs, as a slot or a
rounded pocket) is meshed as a disk. Its middle block was a square halfway
to the loop's quarter points, which on the crank's 6:1 pocket floor
squashed elements to a scaled Jacobian of 0.16. The block is now a
rectangle on the region's principal axes, inset by the same distance all
round (the old square on a circle), its corners paired with the loop nodes
nearest their diagonals, its sides spaced as the nodes they pair with, and
the O-grid is smoothed (untangled first) before the validity check.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
project_trimmed accepted the analytic projection within a fifth of the nearest
triangle's size; a plane face's triangles can span the whole face, so nodes in a
3 mm fillet landed on the untrimmed box planes (mesh volume = the unfilleted box).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Topology::split cuts a block at given fractions and every block chained to it
through parallel edges, orienting the fractions through the chain, so the
topology stays conforming. A certified-invalid element is reported with its
block, cell, centre and the block vertex and blocks meeting there; the mesh is
never emitted.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Each source node follows its own path (a direction or the section normal)
to the target, found by Newton on the target's tangent plane; layers are
graded by a bias; side faces, when given, hold the boundary nodes of every
layer (alternating projections at the target), and interior nodes take the
boundary-residual correction. Source nodes are kept, so a section taken from
a neighbouring mesh conforms with it.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A block topology (carved grid, butterfly and seven-block sphere templates,
O-grid, extrude, connect) projected onto a body: outer block faces onto their
smooth face groups, edges onto the curve of two targets and vertices onto the
point of three by tangent-plane iteration, nodes by transfinite interpolation,
then Winslow smoothing with the boundary on the geometry and a compass search
on the worst elements.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The swept cross-section's decomposition:
- An opening with concave corners gets a layout that continues its sides to the outer loop
(side strips and corner blocks, every corner near 90°). The thin air ring round the Pi
enclosure's square pedestal was left to the free mesher, which put a node 1e-5 from the
opening's corner: edge ratio 341,515.
- A piece's score is capped by its quadrilaterals' aspect against their longest edge or the
target size, so thin strips and pieces much smaller than the elements no longer score as
square blocks; the free mesh is scored alike for "do no harm".
- A disk is not cut into wedges round its centre (its O-grid is the scheme).
- Cuts whose pieces cannot be given division counts together (mapped pieces round a hole that
chain back to a longer side) are refused, instead of failing the whole cross-section.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
hex_mesh_swept_cells lays out one cross-section for several cells: every
cell's walls (its cut faces included) are imprinted together, every cell's
levels are levels of all, one interval assignment and one set of layers,
and each region of each level interval is filled by the cell it lies in.
Cells meet node for node across every cut, T-junctions included.
mesh.cells sweeps the cells of each design body together first and meshes
cell by cell only what does not sweep together (saying why); the reply
gives every cell's volume, scaled Jacobian and edge ratio.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Four triangles round a point (a square cut along both diagonals) share their
free half-diagonals in pairs, so those alone cannot make every loop even when
the square's perimeter is odd; the parity repair kept raising them until the
step cap. A loop that keeps coming back now lets its coupled curves move.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
fieldcraft_model::progress: a host installs a Progress on the worker thread
and reads its snapshot from another; the engine names the step being solved,
the nonlinear solver its load factor, the explicit solver its time, the
fluid solver its steps, transient heat its increments and the tet mesher its
stage and pass. Without one installed every report is a no-op (#322, #357).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Delaunay refinement split a boundary face edge at its midpoint even when that
midpoint lay inside the diametral sphere of a feature edge beside it. Each such
split halves the face vertices' distance to the curve, so they piled up against
it (the heated bracket grew face vertices 0.016 mm from a 4 mm-sized edge), the
improvement schedule could not lift the tetrahedra there to its target, and
inserted vertex after vertex around them: 29257 elements and about two minutes
to open instead of 23641 and 6 s. The SolidCraft pin move (4c91f9b) added one
interior vertex to the bracket's end faces, which changed the CDT enough to
expose it.
Following Shewchuk (1998), an encroaching midpoint now splits the encroached
feature edge instead.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A region of an extrusion's (or revolution's) cross-section that no
structured scheme fits is now cut by straight lines into blocks that fit,
before interval assignment, so the cuts are curves of the arrangement and
their counts are assigned with the rest; nothing reaches the model
(hex::decompose, after Tam and Armstrong's medial-axis subdivision and Li,
Armstrong and McKeag's primitives).
Per region: several holes are separated by lines across the gaps between
neighbouring holes; a piece with one hole gets the O-grid layout whose
pieces score best (lines from the outer corners towards the hole or along
their bisectors, from the hole's corners, or along four directions from
the hole); pieces without holes are cut by a two-ply search over lines
from concave corners and fillets and from convex corners. Candidates are
scored by meshing the pieces with their schemes (smallest corner scaled
Jacobian). A region's blocks are kept when fair (at least 0.5) or no worse
than its free mesh, and cuts never end inside a seeded curve.
This replaces the cuts from reflex corners along an edge. Tests on an L,
a T, a plate with a hole, with a slot and with three holes, and the half
crank's cross-section: every region structured, the quads conforming and
the smallest corner scaled Jacobian bounded. The half crank arm now
extrudes in 12 structured regions with a hex20 minimum scaled Jacobian of
0.37 (the arm meeting the bosses 20 degrees off tangent bounds it) where
it had 2 free regions and 0.009.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The schemes, interval constraints, curve nodes and region meshes of a
multi-level sweep's cross-section move out of layered::mesh into
hex::section, with the curve placement (seeds, projection onto walls)
passed in, so the cross-section can be meshed on its own.
region::mesh_structured gives a scheme's mesh or None where it would fold,
without falling back to the free mesher. No change in behaviour.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A cross-section region with three corners (a fillet's quarter disk, a
pocket corner cut off by a partition) was left to the free all-quad
mesher. It now gets midpoint subdivision's triangle primitive (Tam and
Armstrong 1991; Li, Armstrong, McKeag 1997): lines from a centre to a
node on each side split it into three mapped blocks, the interior then
smoothed and every quadrilateral checked (a fold falls back to free).
Interval assignment gains dominance constraints (a side shorter than
the other two together) so the split always exists.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
`quality::conformity` checks a solid mesh for cracks: the free faces must
close up (every corner edge on exactly two), no two distinct nodes may
coincide, and every element edge has one mid-side node. The hex tests
assert it for every method, hex20 included, and the crank arm sample's
7274 hex20 is conforming (#260: the disjoint lines are a display issue).
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
The seed's spacing becomes size-field samples the field grades from, and
after coarsening its nodes are put on the feature curve and pinned, so the
edge has exactly the seeded divisions at the seeded spacing. The quality
report gives, per seed, the boundary edges along it.
Part of #230.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
A seed is matched to a mesher's curve by position (ends and middle within the
two tessellations' tolerance), which also orients its bias. Interval
assignment holds exact seeds, raises minimums and takes free seeds as goals;
an equality, loop minimum or parity it cannot meet with the exact seeds held
names them. Seeded curves get the seed's spacing. Extrude and revolve seed
cross-section curves and the layers of a level interval; sweep and mapped
seed their B-rep edges; cells seed the shared edge once, so both cells keep
it and stay conforming.
Part of #230.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
fieldcraft_mesh::mirror reflects a region's tet4, tet10, wedge6, hex8 and hex20
elements across a plane. The copies list their nodes in reflected order (corners
swapped, mid-side nodes following their edges), so every copy is right-handed;
reflected_faces and reflected_edges give the copy's face and edge over the same
nodes. Copies of the nodes on the plane are merged with the originals through
join::merge_coincident, so the region and its image form one conforming mesh.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
Model::merge_nodes replaces merged nodes by their survivors in elements (node
order kept, so face and edge tags hold) and in set node lists, moves a vertex
tag to an untagged survivor, and refuses a merge that would collapse an
element. fieldcraft_mesh::join::coincident_nodes / merge_coincident find the
nodes within a distance of a lower-labelled survivor, deterministically.
Meshing cell by cell and mirroring use them; node merging commands will too.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
