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Hi,

I am performing 2D TELEMAC model for an urban area. I have a 1x1 m resolution DEM. Thus, I would like to have the mesh triangle side length 1m.
I applied this on an area 1x1 km and it took time but worked.
Now, I am working on a more powerful computer and increased the simulation area. The number of nodes is 8840419 but it takes a too long time to generate the mesh ( more than two days until now and it only reached 63%). The Blue Kenue is only using a few amounts of the available RAM, CPU,.. (for example, it uses only 6 GB from 294 available GB). I would like to ask if there is a way to make it faster, or is it another way to generate mesh faster.

Thanks in advance
Best regards.

Hi,

if you want to generate a regular triangular mesh based on a DEM, you can use the triangulation option in Blue Kenue: File -> New -> Triangulation.

This should be much faster.

Hope this helps,
Clemens

Hi Clemens,
Thank you for your reply.
I tried to do it but it only creates one or two triangles. Is there a pdf or tutorial that I can get more information about it.

Best regards.
Omar

Try...

Select the DEM in the workspace and use File->Save As...
Choose t3s as the FileType.

Hope this helps... Martin

I import the DEM as a ArcShapefile. Thus, it is not possible to save it as t3s File type

Hi,

I waited for three days for Blue Kneue to create the mesh and the result is as attached. Does anyone have an explanation? recommendations?

Best regards.
Omar

Hi
It seems your are is regular.
Do you have buildings in it?

If no, I would say it will be probably easier and faster to create the mesh by a python script. You could create a grid with 1m x 1m size and split the square in 2 triangles...

Hi,
Thank you for your response.
Yes, it is regular. I have buildings and I only define the buildings with a higher roughness to allow some water to pass through it. Can you recommend a script or should I write a script?

Best regards.
Omar

Hi
I don't have a known script in mind...
But with python and numpy, it's not so hard to write a small script which create the nodes (on a regular basis) and the element...
You could then directly write the selafin file (potentially with the python api of hermes)
Otherwise, you could probably more easily generate the T3S file which could be read by BK to generate the selafin file. T3S file format is available in the BK documentation

Hope this helps

Ok there we are. Your input is not a regular grid or DEM as per definition but a shape file. Totally different starting point for us in order to give you some useful answers. And no wonder that the mesh generator fries...

Maybe the easiest and most convenient way, using Blue Kenue:
1) Create a regular grid which covers your domain and corresponding cell sizes: -> File -> New -> Regular Grid
2) Interpolate Shape Points to the grid: File -> New -> 2D Interpolation. In your case as interpolation method you can use "Nearest Neighbor". Or maybe before you have to save the shape file as xyz point file or other Blue Kenue format.
3) Save the regular grid as 2D T3 Scalar Mesh as Martin already said.

Hope this works,
Clemens