User Forum of Software BASEMENT

BASEMENT
Basic Simulation Environment for computation of environmental flow and natural hazard simulation
Laboratory of Hydraulics, Hydrology and Glaciology (VAW)
ETH Zurich
Basement_Logo

You are not logged in.

#1 2014-11-26 04:45:07

tristan
User
Registered: 2014-09-09
Posts: 4

Errormessage Editing breakline

Hello,

trying to mesh (elevation and quality) once I get error messages for some breaklines “no elevation data point found at (x/y)”. First times it was reasonable, I corrected. After a time I get always the same error messages for the same point(s). Correcting  in different ways:
completely deleting this part of the breakline - the same message for the same nonexistent coordinates like before,
redigitizing the breaklines - the same error message for the same coordinates.
The same results after deleting the critical points.
Also I tried with completely new shapefiles for my breaklines with newly digitized lines and get the same result.

When I try Quality meshing I get a Phyton-message with “AttributeError:  ‘NonType’ object has no attribute ‘type’” (runTriangle.py, line 179 or other).

It seems to me the corrections don’t arrive. Is this a QGIS-problem or a problem with the meshmachine? Or is this only my problem? Does somebody can give me an explanation or help?
Thank you.

Offline

#2 2014-11-27 11:35:13

Christian Volz
User
Registered: 2014-09-04
Posts: 31

Re: Errormessage Editing breakline

Hello tristan,

it is always difficult to solve such problems without having the data. However, the problem with the missing data for breaklines is a common one. It must be understood, that a breakline consists of a number of points in the shape format. These points are connected to form a line. For all of these points you MUST provide x-y-z points (with elevation!) in the point-dataset. If not all points of the breakline are covered by elevation points, the elevation meshing will not work. Probably your datasets miss some elevation points for the breaklines, resulting in this error.

Regarding the other error message at quality meshing: we have actually no idea what causes this error message. There seems to be a problem we have not expected to happen and which is not handled by the plugin. I recommend to take a look into our tutorial. Try the quality meshing with the original data, provided with our tutorials. If the quality meshing works with the tutorial-data, then it is probably not a problem with BASEmesh but with your data. In this case, you should check your data if it is really formatted in the correct way, has all necessary fields (etc.).

Hopefully this answer is of some help for you. If your problems persist, do not hesitate to inform us.

Best regards,
Christian

Last edited by Christian Volz (2014-11-27 12:09:49)

Offline

#3 2014-11-27 19:00:48

tristan
User
Registered: 2014-09-09
Posts: 4

Re: Errormessage Editing breakline

Hello Christian,

thank you for your response. My first problem with the missing points in breaklines seems to be solved. Very helpful for inspection to the correct placements of the vertices are the plugins “spatialqueryplugin” and “vertices counter”. The same for checking boundary-polygons.

With the vertices counter I found out some nonvisible residues from deleted segments (number of vertices =1) which caused probably the python-message:

Traceback (most recent call last):
  File "C:/Users/tristan/.qgis2/python/plugins\BASEmesh\elevation\elevation_dialog.py", line 162, in accept
    success = triangle.extractSegments(breaklinesLayer, False, True)
  File "C:/Users/tristan/.qgis2/python/plugins\BASEmesh\tools\runTriangle.py", line 205, in extractSegments
    if feat.geometry().type()==QGis.Line: # double check for feature geometry
AttributeError: 'NoneType' object has no attribute 'type'

After deleting these residues meshing works fine.

Best regards,
Tristan

Offline

Board footer

Powered by FluxBB