Improving 2d mesh accuracy

[skypalat]

Hi! I've been using SeismicMesh recently to try to generate a 2D mesh from a distance function I have defined. The results so far have been quite good, but not exact to the distances specified by my function (i.e. some edges are shorter/longer than they should be by some small, but not insignificant amount).

My particular goal relies on generating a very accurate 2D mesh, so I was wondering if there was any cleanup functions that you think could help refine the mesh to the correct edge lengths, or at least remove some of the more incorrect edge lengths? I have tried setting "perform_checks" to True, but this didn't help too much.

Any guidance you can offer on this issue would be much appreciated. Thanks in advance for your help!

[krober10nd]

Hi @skypalat. What does the error look like in the mesh? Can you provide some images?

You can try manipulating this L0mult parameter. It multiplies the bar lengths by a constant factor to drive movement of the mesh nodes to a convergent state in which the majority of triangles are equilateral. Perhaps make the numerator 0.4 to 0.3 or 0.2 and measure the errors.

SeismicMesh/SeismicMesh/generation/mesh_generator.py

Line 418 in 982ab5b

L0mult = 1 + 0.4 / 2 ** (dim - 1)

The images you attach will be helpful in better understanding the problem.

[skypalat]

Hi @krober10nd thanks so much for the reply! Here's a picture/map of my desired edge length distribution an image of the mesh with annotations where things are notably going wrong, and a zoom in on the center of the mesh so you can actually see the edges well

I will try to manipulate the L0mult parameter and see if that helps. Thanks again!

[krober10nd]

Ah very interesting. It also seems there's some element cleaning occurring at the end as well. This could lead to some inaccuracies.

Could you share the example mesh generation script so I can also try some things locally?

[skypalat]

For sure. Here's the script as well as the example data (just change the path in the jupyter notebook and everything else should run as is, although I use a plotting mechanism from the pydistmesh package that you may want to replace)
seismic_ex_data.txt
Link to jupyter notebook: https://drive.google.com/file/d/1P-uEzZZ_KD3H5J1EFFbzGiaFWM6FNLfp/view?usp=sharing