# [Gmsh] 3D meshing won't work

Magdalena Stolarska stolarsk at math.umn.edu
Wed May 5 05:09:06 CEST 2004

```Hi.  I have a few of questions.  I apologize if they are elementary --
I'm fairly new to this and have a hard time finding an explanation on the
web.

1) What exactly is consistent elementary surface orientation (as described
under the Surface Loop explanation in the documentation of Gmsh 1.51)?

2) I've attached the *.geo file that I am working on -- For some reason,
the 2D surface meshing works okay, but the 3d meshing is not working (I
just end up with a 2d mesh).  Depending on what I choose the
characteristic length to be, I get a variety of complaints.  For example,
for a characteristic length of 0.1, I get no complaints other than one
error: "Error : No contour".  For a characteristic length of 0.05 I get
complaints like (in addition to the one above)
Error : Missing edge without any intersection (0.55,0.1,0.3) (0.55,0,0.3)
and
Warning : *Unrecoverable* face (0 <--> 1=2*(3-1)-3)
For a characteristic length of 0.04 the only error I get is "Error : No
contour".

>From the little that I know gmsh, I am thinking that the fact that there
is no 3d mesh has to do with either the surface loop ordering or the
error:"Error : No contour".  I checked all of my Line Loops, and the
ordering seems okay, so could you at least please let me know what the no
contour error could mean.  Any other suggestions would also be greatly
appreciated.  Thank you.

M.S.
-------------- next part --------------
// morph_rect.geo

h = 0.04;

Point(1) = {0, 0, 0, h};
Point(2) = {1, 0, 0, h};
Point(3) = {1, 0, .5, h};
Point(4) = {0, 0, .5, h};
Point(5) = {.45, 0, .2, h};
Point(6) = {.55, 0, .2, h};
Point(7) = {.55, 0, .3, h};
Point(8) = {.45, 0, .3, h};
Point(9) = {.45, .1, .2, h};
Point(10) = {.55, .1, .2, h};
Point(11) = {.55, .1, .3, h};
Point(12) = {.45, .1, .3, h};
Point(13) = {0, 1, 0, h};
Point(14) = {1, 1, 0, h};
Point(15) = {1, 1, .5, h};
Point(16) = {0, 1, .5, h};
Point(17) = {.9, 1, .2, h};
Point(18) = {1, 1, .2, h};
Point(19) = {1, 1, .3, h};
Point(20) = {.9, 1, .3, h};
Point(21) = {.9, .7, .2, h};
Point(22) = {1, .7, .2, h};
Point(23) = {1, .7, .3, h};
Point(24) = {.9, .7, .3, h};
Point(25) = {.9, .9, .3, h};
Point(26) = {.9, .9, .2, h};
Point(27) = {.1, 1, .3, h};
Point(28) = {.1, .9, .3, h};
Point(29) = {.1, .9, .2, h};
Point(30) = {.1, 1, .2, h};

Line(1) = {1,2};
Line(2) = {2,3};
Line(3) = {3,4};
Line(4) = {4,1};

Line(5) = {5,6};
Line(6) = {6,7};
Line(7) = {7,8};
Line(8) = {8,5};
Line(9) = {6,10};
Line(10) = {7,11};
Line(11) = {8,12};
Line(12) = {5,9};
Line(13) = {9,10};
Line(14) = {10,11};
Line(15) = {11,12};
Line(16) = {12,9};

Line(17) = {2,14};
Line(18) = {3,15};
Line(19) = {4,16};
Line(20) = {1,13};

Line(21) = {13,14};
Line(22) = {14,18};
Line(23) = {18,17};
//Line(24) = {17,20};
Line(25) = {20,19};
Line(26) = {19,15};
Line(27) = {15,16};
Line(28) = {16,13};

Line(29) = {20,25};
Line(30) = {25,24};
Line(31) = {24,23};
Line(32) = {23,19};
Line(33) = {17,26};
Line(34) = {26,21};
Line(35) = {21,22};
Line(36) = {22,18};

//Line(37) = {17,20};
Line(38) = {26,25};
Line(39) = {21,24};
Line(40) = {22,23};
//Line(41) = {18,19};

Line(42) = {27,28};
Line(43) = {28,29};
Line(44) = {29,30};
Line(45) = {30,27};

Line(46) = {29,26};
Line(47) = {30,17};
Line(48) = {27,20};
Line(49) = {28,25};

Line Loop(50) = {1,2,3,4};   Line Loop(51) = {5,6,7,8};
Plane Surface(52) = {50,51};   //Plane Surface(53) = {51};
Line Loop(54) = {9,14,-10,-6};       Plane Surface(55) = {54};
Line Loop(56) = {13,14,15,16};       Plane Surface(57) = {56};
Line Loop(58) = {5,9,-13,-12};       Plane Surface(59) = {58};
Line Loop(60) = {-7,10,15,-11};      Plane Surface(61) = {60};
Line Loop(62) = {12,-16,-11,8};      Plane Surface(63) = {62};

Line Loop(64) = {17,22,-36,40,32,26,-18,-2};  Plane Surface(65) = {64};
Line Loop(66) = {-25,29,30,31,32};            Plane Surface(67) = {66};
Line Loop(68) = {23,33,34,35,36};             Plane Surface(69) = {68};
Line Loop(70) = {30,-39,-34,38};              Plane Surface(71) = {70};
Line Loop(72) = {35,40,-31,-39};              Plane Surface(73) = {72};

Line Loop(74) = {22,23,-47,45,48,25,26,27,28};
Plane Surface(75) = {74};
Line Loop(76) = {49,-29,-48,42};       Plane Surface(77) = {76};
Line Loop(78) = {46,-33,-47,-44};      Plane Surface(79) = {78};
Line Loop(80) = {42,43,44,45};	       Plane Surface(81) = {80};

Line Loop(82) = {-19,4,20,-28};        Plane Surface(83) = {82};
Line Loop(84) = {1,17,-21,-20};        Plane Surface(85) = {84};
Line Loop(86) = {-3,18,27,-19};        Plane Surface(87) = {86};

Line Loop(88) = {43,46,38,-49};        Plane Surface(89) = {88};

Surface Loop(88) = {85,83,87,75,77,81,79,89,71,67,73,69,65,52,59,63,57,55,61};
Volume(89) = {88};

//Physical Surface(100) = {88};
//Physical Volume(101) = {89};
```