Fine Volume mesh makes NetGen.exe closing

Netgen
1

Hi,

I have a simple example on a .geo file where the volume meshing is working with ver. 5.3.
It is not working with ver. 6.2.2301 when meshing is defined as “Fine” or “Very Fine”.
The software simply close without any further message.
I have worked worked with different boundingboxes without succes.

Can someone explain it?

PS I cannot attach the geo file. There seems to be an error in the browser.
So here it comes:

algebraic3d
solid vol0 = polyhedron (
0.0,1.0,1.18;
0.34,2.3,1.18;
0.0,2.3,1.18;
0.34,1.0,1.18;
0.34,2.3,1.74;
0.34,1.0,1.74;
0.84,2.3,1.74;
0.84,1.0,1.74;
0.84,2.3,1.18;
0.84,1.0,1.18;
0.92,2.3,1.18;
0.92,1.0,1.18;
0.92,2.3,0.6;
0.92,1.0,0.6;
0.0,2.3,0.6;
0.0,1.0,0.6;
;
 1, 2, 3;
 1, 4, 2;
 4, 5, 2;
 4, 6, 5;
 6, 7, 5;
 6, 8, 7;
 8, 9, 7;
 8, 10, 9;
 10, 11, 9;
 10, 12, 11;
 12, 13, 11;
 12, 14, 13;
 14, 15, 13;
 14, 16, 15;
 16, 3, 15;
 16, 1, 3;
 4, 8, 6;
 4, 10, 8;
 4, 14, 10;
 10, 14, 12;
 1, 16, 4;
 4, 16, 14;
 13, 9, 11;
 9, 5, 7;
 15, 2, 13;
 13, 2, 9;
 9, 2, 5;
 15, 3, 2);
tlo vol0;
solid vol1 = polyhedron (
1.1,0.0,0.6;
0.92,2.3,0.6;
1.1,2.3,0.6;
0.92,0.0,0.6;
0.92,2.3,1.18;
0.92,0.0,1.18;
0.84,2.3,1.18;
0.84,0.0,1.18;
0.84,2.3,2.09;
0.84,0.0,2.09;
1.76,2.3,2.09;
1.76,0.0,2.09;
1.76,2.3,0.0;
1.76,0.0,0.0;
1.1,2.3,0.0;
1.1,0.0,0.0;
;
 1, 2, 3;
 1, 4, 2;
 4, 5, 2;
 4, 6, 5;
 6, 7, 5;
 6, 8, 7;
 8, 9, 7;
 8, 10, 9;
 10, 11, 9;
 10, 12, 11;
 12, 13, 11;
 12, 14, 13;
 14, 15, 13;
 14, 16, 15;
 16, 3, 15;
 16, 1, 3;
 1, 6, 4;
 6, 10, 8;
 1, 12, 6;
 6, 12, 10;
 1, 14, 12;
 1, 16, 14;
 11, 5, 9;
 9, 5, 7;
 13, 3, 11;
 11, 3, 5;
 15, 3, 13;
 5, 3, 2);
tlo vol1;
solid vol2 = polyhedron (
0.0,1.0,2.35;
0.84,2.3,2.35;
0.0,2.3,2.35;
0.84,1.0,2.35;
0.84,2.3,1.74;
0.84,1.0,1.74;
0.0,2.3,1.74;
0.0,1.0,1.74;
;
 1, 2, 3;
 1, 4, 2;
 4, 5, 2;
 4, 6, 5;
 6, 7, 5;
 6, 8, 7;
 8, 3, 7;
 8, 1, 3;
 1, 6, 4;
 1, 8, 6;
 7, 2, 5;
 7, 3, 2);
tlo vol2;
boundingbox (-87.12,-113.85,-116.325;88.88,116.15,118.675);

Erik

2

Hi Erik,

I highly recommend to switch to OCC - geometry modeling. Here is also a docu to build a polyhedron from faces:

https://docu.ngsolve.org/latest/i-tutorials/unit-4.4-occ/workplane.html

The OCC interface is under active development, possible bugs or missing features will be fixed quickly.

Joachim

3

for getting started, I converted your first polyhedron to occ:

polyhedron.ipynb (3.0 KB)
polyhedron.html (639.9 KB)

However, using OCC you would probably construct the solid differently,
using 2d drawing in the WorkPlane, and then extrude.

Joachim