User Forum of Software BASEMENT

ako

User

Registered: 2020-05-29

Posts: 2

ValueError: Input nodes may not coincide

Hi,

I have two problems using BASEmesh v2 for the grid generation:

- Quality mesh: I want to generate the quality mesh with 3D breaklines, input points, quality points and stringdefs. The grid layer of the quality mesh is generated but I can't see any element or vertices in QGIS. I have no error statement though...
- Interpolation: I can't interpolate the elevation on the above mentioned quality mesh. I obtain the following error message: "ValueError: Input nodes may not coincide".

I use QGIS v3.12. The same breaklines (3D) are used for the elevation and for the quality mesh. The same input points (3D) are used for the elevation and for the quality mesh. These inputs points where extracted from a previous .2dm mesh.

Do you have any idea how to solve it? Thank you!
Best regards,
Aurélie

sua87

User

From: Bern

Registered: 2017-05-26

Posts: 21

Re: ValueError: Input nodes may not coincide

Hi Aurélie

First problem: you need to turn on the native mesh rendering under the properties of the imported mesh.

Second problem: We experience the same problem as you do (QGIS 3.10.10) and have not found a proper solution until now... I would really appreciate a hint or a input.

Thanks.
Andi

Stephan Kammerer

Developer

Registered: 2015-03-31

Posts: 67

Re: ValueError: Input nodes may not coincide

Hey,

the error message: "ValueError: Input nodes may not coincide" might be caused by mesh verticeslocated too close to each other (relativ to your domain size). Make sure to check your input data and also the intermediate mesh layers. Like shown in the figure below, a missing breakline vertex lead to a "nest" in the Qualiy mesh, which than caused the same error when trying to execute the Interpolation 

Matteo Facchini

Developer

From: Trento

Registered: 2014-09-05

Posts: 278

Re: ValueError: Input nodes may not coincide

This happens to me also when 3 or more lines are intersecating at a vertex. Usually, if I zoom in, I find two of them "snapped together" and the third a bit far from the other. It happens particularly when I have stringdefs and breaklines meeting at a vertex!

jonas

User

From: Lausanne

Registered: 2021-10-01

Posts: 1

Re: ValueError: Input nodes may not coincide

Hi,

I also get the error message "ValueError: Input nodes may not coincide" when interpolating the element elevation from a DEM. There is however no "nest" (as suggested in post #3) in my quality mesh.

I use QGIS version 3.10.4 on Ubuntu 20.04.2 LTS

Have you any idea of other issues generating this error message ?

Best regards,
Jonas