User Forum of Software BASEMENT

UP

User

Registered: 2025-03-23

Posts: 14

Mesh via triangle failed

Meshing via triangle failed
Node result file not found.

Prefix of triangle output-files: Qual_Mesh

Plugin directory: C:/Users/LENOVO/AppData/Roaming/QGIS/QGIS3/profiles/default\python/plugins/basemesh_v1

Triangle successfully initialized

Processing input data...

Layer with breaklines specified: Breaklines

> Layer with regions specified: Region_points

- field with maximum element size data: max_area

- field with material index data: MATID

- Field with hole marker: hole

TRIANGLE INPUT file Qual_Mesh_Quality.poly successfully written

> EXECUTION OF TRIANGLE... <

Opening C:/Users/LENOVO/AppData/Roaming/QGIS/QGIS3/profiles/default/python/plugins/basemesh_v1/triangle_tempfiles/Qual_Mesh_Quality.poly.
Constructing Delaunay triangulation by divide-and-conquer method.
Recovering segments in Delaunay triangulation.
Removing unwanted triangles.
Spreading regional attributes and area constraints.
Adding Steiner points to enforce quality.
Error:  Ran out of precision at (508538.838454, 3074459.22696).
I attempted to split a segment to a smaller size than
  can be accommodated by the finite precision of
  floating point arithmetic.
Try increasing the area criterion and/or reducing the minimum
  allowable angle so that tiny triangles are not created.

It is truly disgusting that I can't add the screenshot easily.

After this error I changed the boundary and proceed and made the 2dm file and basement model but while running basement, node id error comes Says: "Simulation stopped due to error:
The edge string 'Lake' is not correct. No edge found fo these node number 4796 5523. Please correct the edge string in the command file. basement terminated". While checking this node in QGIS I found that these nodes comes outside the lake breakline I made. when correcting it another node error comes again.

What should I do now? i used Basemesh v1.4.6 and basement 2.8.2.

Last edited by UP (2025-04-04 15:45:01)

UP

User

Registered: 2025-03-23

Posts: 14

Re: Mesh via triangle failed

While trying making mesh via Basemesh v2, i got this error,

-------------------------------------------
Following nodes don't belong any element!!!
-------------------------------------------
63059    63061    63103    63105    63107    63109    63111    63113    63115    63117    63119   
63121    63123    63125    63127    63129    63131    63133    63135    63137    63139    63141   
63143    63145    63147    63149    63151    63153    63155    63157    63396    63400    63404   
63408    63412    63416    63420    63424    63428    63432    63436    63440    63444    63448   
63452    63456    63460    63464    63468   

I got this error in .err file. what are the reasons for these sort of errors?

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 141

Re: Mesh via triangle failed

Hi

My guess is that you should snap some breaklines or boundary lines (enable snapping in QGIS). 
In the Error message there is a problem at the coordinate (508538.838454, 3074459.22696), check what is happening there!

I hope this helps!

Br, Lukas

UP

User

Registered: 2025-03-23

Posts: 14

Re: Mesh via triangle failed

I solved this coordinate error by changing the boundary. After that mesh is formed and I made the basement simulation file with both basemesh v1.4.6 and V2 but the error appears in the basement as
Simulation stopped due to error:
The edge string 'Lake' is not correct. No edge found for these node number 4796 5523. Please correct the edge string in the command file. basement terminated. This is for preprocessing done with basemesh v1.4.6.

Following nodes don't belong any element!!!
-------------------------------------------
63059    63061    63103    63105    63107    63109    63111    63113    63115    63117    63119   
63121    63123    63125    63127    63129    63131    63133    63135    63137    63139    63141   
63143    63145    63147    63149    63151    63153    63155    63157    63396    63400    63404   
63408    63412    63416    63420    63424    63428    63432    63436    63440    63444    63448   
63452    63456    63460    63464    63468   
This error comes in basement when basemesh V2 is used.

Anyways error came. What should I do?

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 141

Re: Mesh via triangle failed

simplify your mesh and then step by step add more complexity. E.g. start only with boundary, without breaklines and edge strings (and check your mesh in QGIS). Also check your edge strings, do they cross breaklines?

UP

User

Registered: 2025-03-23

Posts: 14

Re: Mesh via triangle failed

https://drive.google.com/drive/folders/ … sp=sharing

I have included screenshots of error and the file created with QGIS file. Please have a look on it. I couldnt figure out the error. I have uploaded file created with both basemesh v1.4.6 and v2.

Last edited by UP (2025-04-09 15:10:45)

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 141

Re: Mesh via triangle failed

It does not make sense to define all breaklines as a stringdef. Remove the long stringdefs in your basement (.bmc) input file and only use the inflow and outflow stringdefs.

UP

User

Registered: 2025-03-23

Posts: 14

Re: Mesh via triangle failed

i have one dought that i defined lake and left and right side breaklines on both side of lakes, but nodes comes out of lake boundary and breaklines boundary, comes of the area that are between them. I am doing this project of GLOF, avalanche enters the lake and overtops the moraine dam. Will I get error if I didn't defined all nodes used in the project? i have to give inflow hydrograph of avalanche on the lake but the basement says to give inflow on the outer boundary edges. i have lake inside the breaklines.
i need guidance on this topic.

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 141

Re: Mesh via triangle failed

I would recommend you to do all available tutorials on hydraulic 2d modelling. Furthermore make sure you understand the concept of boundary conditions (where you need stringdef) and the concept of breaklines (where you don't need stringdef).