TetWild creates invalid surface connectivities.

[nburgess350]

Hi,
I was recently using TetWild to do some re-meshing before some finite-element simulations. When generating a particularly coarse mesh with --epsilon = 500, I got a mesh that has 4 boundary faces incident on the same edge (see attached picture). Using a higher value of epsilon seems to make this go away but I thought you might want to know.

Best Regards and Thanks,
Nick

[qnzhou]

Thanks Nick! Does this happen at a particular thin feature of the input?

[jdumas]

I don't think there is anything in TetWild's algorithm that prevents it from creating non-manifold edges. I mean, if the envelope is too large, and surface vertices get pinched into a single edge within the envelope, the result is still technically correct (and I don't think there is any topological check in TetWild's update scheme). Decreasing the epsilon should make it go away as you observed.

[Yixin-Hu]

Jeremie is correct. Large envelope would make the output "pixelized".