Mesh connectivity in 3d

General Discussion
1

Hi FreeFem community,

I have a 3d mesh and I need to get the data about the number of tetrahedrons and to obtain the adjacent elements of each one. According to the documentation, in 2d i can compute the number of triangles according to the command Th.nt and the adjacencies by Th.adj

https://doc.freefem.org/documentation/mesh-generation.html#mesh-connectivity-and-data

However, it is not specified how to obtain the number of tetrahedrons in 3d. Also, I need to specify each element by its number to compute its adjacencies by using the above command.

Best Regards
Jacob

2

Hello,
You can use the following code to test and visualize:

load "msh3"

mesh3 Th = cube(2, 1, 1);
cout << "Volume: " << Th.measure << endl;
cout << "Number of tetrahedron: " << Th.nt << endl;
cout << "Number of vertex: " << Th.nv << endl;
cout << "Number of boundary triangle: " << Th.nbe << endl;
plot(Th);

This section explains a little bit.

3

Hello,

Thank you very much for your reply. Yes, finally worked by using the commands you mentioned in the previous post.

Best regards