[Gmsh] Default scale format, change scale

Geordie McBain gdmcbain at freeshell.org
Wed Jul 22 01:29:43 CEST 2009


On Tue, Jul 21, 2009 at 8:47 PM, Sebastian
Mathiowetz<sebastian.mathiowetz at googlemail.com> wrote:
> Hi there,
> I´ve got a very simple question: in the manual it says that default scaling
> is 1.
> So when I define a straight line from points 0, 0, 0 and 0, 1, 0, is it´s
> size then 1 meter or 1 millimeter or what is the unit scale? I can´t find
> anything in the documentation, but I guess its SI units, so it must be 1 m,
> is that right?eqe
> When I click on the button 1:1 (Set unit scale, or sync scale) at the bottom
> of the GUI window, there just happens nothing...How can I change scale then?
> Thanks very much for any answers!

Gmsh is dimensionless (like say a pocket calculator, a spreadsheet, or
a Fortran compiler is); the length-units are whatever you like.  This
has to be taken into account in whatever you do with the mesh once
you've generated it in Gmsh.
  I think the 1:1 button on the GUI only affects the `scale' of the
view, not the model itself.  Try zooming in or out and then clicking
it to see what I mean.
  I believe the Dilate command of the Geometry model
<http://geuz.org/gmsh/doc/texinfo/gmsh_6.html#SEC37> might be of
interest if you do want to scale things, but I haven't tried it
myself.