[Gmsh] Ignore points for triangulation

[jlsonnette at tiscali.fr]

Dear Gmsh-users,

I have recently installed Gmsh, and I am pleasantly surprised with the
capabilities of Gmsh, and before posing my question I would like to
congratulate the developers and contributors with their achievements.

I am trying out Gmsh to generate a 2D grid for hydrodynamic river
modelling -- shallow water equations.  The river banks have been measured
by surveyors, and the output is produced in an AutoCad file (*.dxf).  With
dxf2geo.pl, I can easily import the file xy coordinates of the river
banks.  Creating a surface with holes (taking out the little islands in
the river), generates a surface to which I can apply the 2D mesh command.

However, sometimes the surveyors have measured more much more detail than
we need in our model, and it seems to me that Gmsh creates a triangle from
each of the points on the river bank, thus in certain areas a grid is
created that is far to detailed for our needs.

Is it possible to let Gmsh ignore some points for the triangulation?  I
have played around with the characteristic length etc, as I learned from
the tutorials, but I am probably confusing things.  I would be very
pleased if someone has some suggestions.  (I do apologise for this
newbie-type question)

I would like to thank you in advance for considering my question.


Jean