Transform: breakElements (NGON & MIXED) to ME in api3

[vincentcasseau]

T.breakElements (NGON & MIXED) returns a ME (thus api3) instead of a list of BEs

Regressions

Apps            : createDragonMesh_t1.py                  : 0m1.87s   : 0m2.26s   : 25/11/25 11h30  : 0%   :   :  FAILED    
Converter       : convertArray2Hexa_t1.py                 : 0m0.45s   : 0m0.47s   : 12/01/26 09h56  : 92%  :   :  OK    
Converter       : convertArray2Tetra_t1.py                : 0m0.45s   : 0m0.39s   : 07/05/24 14h48  : 100% :   :  OK
Transform       : breakElementsPT_t1.py                   : 0m0.48s   : 0m0.39s   : 07/05/24 15h01  : 0%   :   :  FAILED   
Transform       : breakElements_t1.py                     : 0m0.44s   : 0m0.39s   : 07/05/24 15h01  : 100% :   :  OK    

where:

• OK means geometrically identical
• FAILED means different output

Regression breakElementsPT_t1

DIFF: longueur des fils differente pour le noeud: Base.
  - Noms des noeuds de courant qui ne sont pas dans ref:
TETRA,PENTA,HEXA.
  - Noms des noeuds de ref qui ne sont pas dans courant:
TETRA, PENTA, HEXA.

Regression createDragonMesh_t1

This test shows that permuting vertex indices without changing the geometry produces a different output in G.tetraMesher

# - tetraMesher (pyTree) -
import Generator.PyTree as G
import Converter.PyTree as C
import Converter.Internal as Internal
import Post.PyTree as P
import Transform.PyTree as T

def _remap(ext):
    import numpy as np
    np.random.seed(42)

    gcx = Internal.getNodeFromName(ext, 'CoordinateX')[1]
    gcy = Internal.getNodeFromName(ext, 'CoordinateY')[1]
    gcz = Internal.getNodeFromName(ext, 'CoordinateZ')[1]
    ec = Internal.getNodeFromName(ext, 'ElementConnectivity')[1]

    npts = gcx.shape[0]
    # indir maps new -> old
    indir = np.random.permutation(npts)
    gcx[:] = gcx[indir]
    gcy[:] = gcy[indir]
    gcz[:] = gcz[indir]

    # inverse mapping old -> new
    invIndir = np.empty_like(indir)
    invIndir[indir] = np.arange(npts)
    ec[:] = invIndir[ec-1] + 1

a = G.cart((0,0,0), (1,1,1), (10,10,10))
ext = P.exteriorFaces(a)
ext = C.convertArray2Tetra(ext)
ext = G.close(ext)
ext = T.reorder(ext, (-1,))
m1 = G.tetraMesher(ext, algo=1)
_remap(ext)
m2 = G.tetraMesher(ext, algo=1)
C.convertPyTree2File(m1, 'out1.cgns')
C.convertPyTree2File(m2, 'out2.cgns')

print(m1[1], m2[1])

Perfos

Using this test case:

# - breakElements (pyTree) -
import Converter.PyTree as C
import Generator.PyTree as G
import Transform.PyTree as T
import time

a1 = G.cartNGon((-1.,0.,0.),(0.01,0.01,0.01),(110,30,30)) # 3D
a6 = G.cartTetra((-0.4,1.,0),(0.0025,0.0025,0.0025),(100,100,100)) # 3D
a7 = G.cartPenta((-0.4,1.4,0),(0.0025,0.0025,0.0025),(100,100,100)) # 3D
A = [a1,a6,a7]

A = C.convertArray2NGon(A)
a = T.join(A)
C._initVars(a,'{F}={CoordinateX}+{CoordinateY}**2')
res = T.breakElements(a)

Elapsed CPU time of T.breakElements:

• old algo: 5.348 sec
• new algo: 0.594 sec