# Delaunay triangulation in concave domains

**URL:** https://discourse.paraview.org/t/delaunay-triangulation-in-concave-domains/11320
**Category:** ParaView Support
**Created:** [February 2, 2023, 6:36am UTC](https://discourse.paraview.org/t/delaunay-triangulation-in-concave-domains/11320 "2023-02-02T06:36:40Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![nikolasborrel](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/n/a6a055/32.png) [@nikolasborrel](https://discourse.paraview.org/u/nikolasborrel)
#### Post date: [February 2, 2023, 6:36am UTC](https://discourse.paraview.org/t/delaunay-triangulation-in-concave-domains/11320/1 "2023-02-02T06:36:40Z")

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Hi,

I have the following L-shaped domain

 ![Screenshot 2023-02-01 at 22.29.41](https://discourse.paraview.org/uploads/default/original/2X/e/e00185816a26d088f1455da83e518d10fc9fa5ba.jpeg)

and when I apply the Delaunay triangulation, facets are connected across the inner corne due to point distances smaller than the alpha threshold.

 ![Screenshot 2023-02-01 at 22.19.28](https://discourse.paraview.org/uploads/default/original/2X/0/01aff39a8a74d487e58ca9e969f35b08459dbb94.jpeg)

Changing the threshold to a smaller value reduces the problem at the inner corner, but introduces holes inside the domain.

 ![Screenshot 2023-02-01 at 22.20.17](https://discourse.paraview.org/uploads/default/original/2X/7/7cd782e844658baaa20b397275f75899a60c698d.jpeg)

Is there a way to remove the connections near the inner corner? I also have the tetrahedra connection matrix from the data generation, but I cannot find a way to make Paraview use the information (see [this post](https://discourse.paraview.org/t/using-tetrahedra-ids-to-plot-triangulated-data-xdmf/11310)).

I hope someone can help me with this issue, thanks!