[Gmsh] Defining surfaces

[Ruth V. Sabariego]

Hi Steve, 

Surfaces 17, 29, and 41 are generated when extruding. 
You could recover them via an array e.g. vol[] that would contain each time the generated volume and surfaces.

Try replacing the four last lines of your code by:
vol[] = Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{5}; };
vol[] = Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{vol[0]}; };
vol[] = Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{vol[0]}; };
vol[] = Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{vol[0]}; };

vol[0] is the surface opposite to Surface 5
vol[1] is the volume
vol[2] is the outer surface of the cone
vol[3] is the base of the cone 

Regards,
Ruth


On 13 Feb 2013, at 12:55, "Steve Daley" <stevedaley at sky.com> wrote:

> I am a new user to GMSH.  I am having difficulty understanding one of the examples.
> 
> lc = 0.2;
> Point(1) = {0,0,0,lc};
> Point(2) = {1,0,0,lc};
> Point(6) = {0,0,3,lc};
> Line(1) = {1,2};
> Line(2) = {2,6};
> Line(3) = {6,1};
> Line Loop(4) = {2,3,1};
> Plane Surface(5) = {4};
> Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{5}; }
> Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{17}; }
> Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{29}; }
> Extrude {{0,0,1}, {0,0,0}, Pi/2} { Surface{41}; }
> 
> In the example, I can see how Surface{5} is defined and extruded but where are Surface {17} {29} and {41} defined.?
> 
> Is the fact that the surface numbers are incremented by 12 a function of the cone shape ?
> 
> I have developed my own example 3D tet mesh and can generate the quarter of the shape, (ip to the first of the Extrude lines) but don't know how to do the other three quarters  to make up the complete mesh.
> 
> Any help gratefully received.
> 
> Steve Daley
> 
> 
> 
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—
Dr. Ir. Ruth V. Sabariego
University of Liege, Electrical Engineering and Computer Science
http://ace.montefiore.ulg.ac.be/







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