[Gmsh] constructing cones

[Christophe Geuzaine]

phani kumar wrote:

> hi all,
> I am new to using the Gmsh, i want to create a cone with some radius r 
> and height h,how to do this, 

There is no easy way to describe a real cone in Gmsh at the moment: all
non-plane surfaces are constructed using transfinite interpolation (with
a special case for spheres). Jean-Francois added the basic routines
needed to handle conical surfaces a while ago, but they are not yet
available through the scripting language (and have not been tested--if 
you have some free time...).

> one more question i defined a 4 ponits and
> then 4 lines so it formed a rectangle by using Line Loop and i saved it
> as rect.geo , now do i need to compile this file(if so how)  or just i
> have to go and use interactive mode file-open(rect.geo)this will draw
> the rectangle for me and i use mesh to get a mesh for rectangle now i
> have all the elements in mesh with only triangles,i want a mesh which
> should have both triangles and quadrilaterals.how to do this ,

Add a "Recombine Surface" command in the file.

> if i want
> to make mesh coarser(with less triangles  and quadrilatal elements) or
> finer( with more triangles and quadrilaterals)and how to do this.

You can change each point's characteristic length individually, or set a
global factor with "Tools->Options->Mesh->General->Characteristic length
factor".

Best,

Christophe

-- 
Christophe Geuzaine
Applied and Computational Mathematics, Caltech
geuzaine at acm.caltech.edu - http://geuz.org