# [Gmsh] Meshing issue in gmsh

smenon at caltech.edu smenon at caltech.edu
Tue May 13 02:50:53 CEST 2014

```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?

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 "*";

```