[Dune] Progress on CurvilinearGeometry: Time to create custom GridFactory

[Andreas Dedner]

> 2) I suppose the hostgrid (dune-alugrid) would try to do its own metis
routine when I call it.
At least in dune-alugrid loadbalancing would not be done by the
GridFactory. Either the grid
is read on one processor and then one of the grid.loadBalance() methods
is called or the dune-alugrid GridFactory has
some additional methods to read in a preloadbalanced grid - but also in
this case the GridFactory has nothing
to do with the loadBalancing because that is assumed to have already
been done by the user in a preprocessing step.

What you could do is to use the additional methods on the dune-alugrid
GriidFactory
(of course at the moment they are not standard because they were not
discussed yet)
But you could still use these methods in your GridFactory to construct
the grid in parallel.
I guess that is what you would like to do?
That is similar to the example given in the paper on the  parallel
structured grid factory that also
constructs a parallel grid (have a look at Section 2.3.1).

Of course that approach would not work with UG. I don't know what the UG
GridFactory provides in additional
functionality to actually construct a parallel grid (without first
reading it onto one processor and then loadBalancing
after construction which is apparently not what you intend to do?)

If you want to call the grid.loadBalance method but replace the build in
parmetis support by something you have
written then that is also possible (and described in quit some detail in
Section 2.8).

Best
Andreas