Hi Dean,
> > I would also like to show Edge topology displayed on the Irregular
> > quadrilateral grid but the 1D manifold is not implemented on IrregularGrid
> > and making it with the Gridded3DSet is not straight forward as I just have a
> > chain of edges (snake like).
> . . .
I see my answer was a bit unresponsive. You can create your chain
of edges as a UnionSet of Gridded3DSets of manifold dimension = 1.
There is an example of this in visad/examples/DelaunayTest.java
(ssearch for UnionSet).
Good luck,
Bill