Duplicate points in interior regions cause spurious mesh

[sexton]

Created interior region polygon which had duplicate points. Called create_mesh_from_regions, with resulting mesh could not even be seen, as viewed through swollen. In addition, saw diagnostic output of "Vertex 23 does not belong to a triangle". No exceptions were thrown.

[sexton]

This issue is broader than duplicate points (and may not even be duplicate points!). See document at

Z:\inundation\sandpits\jsexton\ANUGA\production\sydney_2006\The Black Screen of Death.doc

which looks at some tests to try and track down what might be causing the black screen. Note, ANUGA is happy to continue integrating, but swollen cannot display the output (maybe at least one value is extreme).

[sexton]

I think this is broader than duplicate points (and probably isn't even that!). See document at

Z:\inundation\sandpits\jsexton\ANUGA\production\sydney_2006\The Black Screen of Death.doc

where a series of tests are described to try and track down the problem. The output can not be viewed in swollen, and this is probably due to either one or a number of extreme values being allocated to the mesh. ANUGA is happy to integrate throughout.

[ole]

We now believe that this is the cause of 'black screen of death'. Removing duplicate vertices resolves it. To automatically protect against this condition we need pmesh to either throw out duplicates or throw out orphaned vertices.

[duncan]

see ticket #23