[Gmsh] Meshing issue in gmsh

[Christophe Geuzaine]

On 13 May 2014, at 02:50, smenon at caltech.edu wrote:

> Hello Christophe,
> 
> I am a post-doctoral researcher and am using Gmsh to do some meshing for
> me. I am having an issue when doing a 3D mesh of a section of a sphere
> with the error message being: "Incompatible surface 22 in transfinite
> volume 28". Would you know what would be the problem causing this error?
> 

It's a limitation of the "transfinite volume" algorithm; currently it can only handle a 5-face topology with 2 triangular faces (a prism with a triangular base). Coding a new case should not be too complicated: the code is in Mesh/meshGRegionTransfinite.cpp.



> Thanks in advance.
> 
> This is my .geo file:
> 
> lc = 0.005;
> length = 0.01;	 //chamber radius/sqrt(2)
> 
> Point(1) = {0,0,0,lc};
> Point(2) = {length,length,-length,lc};
> Point(3) = {-length,length,-length,lc};
> Point(4) = {-length,-length,-length,lc};
> Point(5) = {length,-length,-length,lc};
> 
> Circle(6) = {3,1,2};
> Circle(7) = {2,1,5};
> Circle(8) = {5,1,4};
> Circle(9) = {4,1,3};
> 
> Line(13) = {4, 1};
> Line(14) = {5, 1};
> Line(15) = {2, 1};
> Line(16) = {3, 1};
> 
> Line Loop(17) = {13, -16, -9};
> Ruled Surface(18) = {17};
> Line Loop(19) = {16, -15, -6};
> Ruled Surface(20) = {19};
> Line Loop(21) = {15, -14, -7};
> Ruled Surface(22) = {21};
> Line Loop(23) = {14, -13, -8};
> Ruled Surface(24) = {23};
> Line Loop(25) = {8, 9, 6, 7};
> Ruled Surface(26) = {25};
> Surface Loop(27) = {18, 22, 26, 24, 20};
> Volume(28) = {27};
> Transfinite Line {13, 14, 15, 16} = 10 Using Progression 1;
> 
> Woutlet = 26;
> Wfront = 18;
> Wback = 22;
> Wtop = 20;
> Wbottom = 24;
> WinternalVol = 28;
> 
> Physical Volume("internalVol") = {WinternalVol};
> Physical Surface("outlet") = {Woutlet};
> Physical Surface("front") = {Wfront};
> Physical Surface("back") = {Wback};
> Physical Surface("top") = {Wtop};
> Physical Surface("bottom") = {Wbottom};
> 
> Transfinite Surface "*";
> Recombine Surface "*";
> Transfinite Volume "*";
> 
> 
> 
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh

-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science 
http://www.montefiore.ulg.ac.be/~geuzaine