[Gmsh] Problem making a bulged cylinder using Gmsh

[Rahul]

Hello Geordie,
  Thank you for quick reply and your comments. I am actually new to to Gmsh
and don't know much of it's functions yet. I have drawn some simple
geometries using Gmsh and meshed them successfully. But i want to draw a
spline driven by an equation(such as y=sin(x)) and i was wondering
whether is it possible to draw this equation driven curve in Gmsh.
  Thanks once again and waiting for your reply.

Thanks,
Rahul



On Tuesday 17 January 2012 04:00 AM, Geordie McBain wrote:
> 2012/1/16<rahulsn at iitk.ac.in>:
>> Hello friends,
>>
>> I am having problem making a simple geometry in Gmsh. I am trying to
>> make a cylinder with a bulge. The bulged part of the cylinder is based
>> on a 2D equation. The cylinder part is Ok but i am not able to draw the
>> bulged part of the cylinder in Gmsh. I tried to import the Iges file
>> from solidworks and save it as .geo file but the saved .geo has a lot of
>> splines in it. I was thinking is there a simpler way to draw this
>> geometry directly into Gmsh. I have attached IGS file for the same geometry.
> Hello.  It's usually better to Merge a CAD geometry into Gmsh and then
> work with that; unrolling it as .geo is generally recommended against,
> I believe.  In this fashion, I have made an extremely coarse mesh of
> your surface, as shown in the attached image.  See
> https://geuz.org/trac/gmsh/wiki/STLRemeshing for a proper example.
> That approach certainly works, I have used it to generate
> three-dimensional finite element meshes with millions of tetrahedra
> for FreeFem++.
>
> On the other hand if you do want to work at the .geo level, depending
> on what your "2D equation" is like, you may well be able to define the
> shape in .geo commands yourself.  If it's a little too complicated for
> that, you might be able to write a script in your preferred language
> that writes the .geo file.  Once you've constructed the generatrix, I
> think Extrude with rotation should do the trick, shouldn't it?
> <http://geuz.org/gmsh/doc/texinfo/gmsh.html#Extrusions>