User Forum of Software BASEMENT

Markus

User

Registered: 2014-12-19

Posts: 2

Coincident endpoints of segments

Hello,

I am trying to produce a quality mesh with BaseMesh-Plugin in QGIS. By executing the plugin, there always appears the status message: "Warning: Endpoints of Segment 43 are coincident in C:/..../mesh_quality.poly.". What the error means is not the problem, but how to fix it. I checked the location of these coincident endpoints - they appear at the breakline-boundary-intersection. I tried several times to "resnap" the points or to change something that it works, but this is not the solution because the error is always still existing afterwards. I also checked, if there is more than one vertex at the same place.

The other problem (I suggest that this  is connected to the problem mentioned above) is, that my area points do not really work. If I'm setting the maximal area to 50, BaseMesh produces triangles much bigger than this (I guess the unit is in square meters).

Best regards,
Markus

Last edited by Markus (2014-12-19 11:59:26)

Sam

Developer

From: VAW - ETH Zurich

Registered: 2014-09-04

Posts: 46

Website

Re: Coincident endpoints of segments

Unfortunately I cannot produce such a warning. I tested the following breakline-boundary-intersection possibilities:
- breakline endpoint snapped to boundary vertex, works (recommended case!)
- breakline endpoint is situated outside the boundary, works (triangle puts a vertex at the intersection of the two segments)
- breakline endpoint snapped to boundary segment, does not work (you get extremely small elements)

I suggest to set up a very simple test case, e.g. quality mesh consisting of a 4-point polygon boundary and a 2-point breakline. pls try the above possibilities and compare your results!

as you mentioned the area point issue is likely to be related to the breakline problem...

Markus

User

Registered: 2014-12-19

Posts: 2

Re: Coincident endpoints of segments

Thank you for your answer. I tried your suggested test case but even in this simple try the warning appears. But I discovered, that the area point issue has nothing to do with the warning, respectively with misplaced breaklines. The area point layer itself was incorrect and the solution was found in creating a new one (instead of creating just new points within the layer). Because of the warning message, I was searching in the wrong place.

So the meshing is working now. The warning still appears but BaseMesh seems to deal with it.

Thanks for the help and sorry for the inconvenience...