About tetrahedron definition

General Discussion
1

Can I directly define a tetrahedral mesh in FreeFEM++ using mesh3 Th = tetrahedron(10, 10, 10, [0, 1], [0, 1], [0, 1]);, or are there any prerequisites? Thank you everyone!

2

no code to build a tetrahedron to day in freefem++,
but you can use a file

here a trick to buil mesh with 1 tet.

real[int] xx=[0,1,0,0], yy=[0,0,1,0], zz=[0,0,0,1];
mesh3 Th=tetgconvexhull(xx,yy,zz,region=1,label=3);
savemesh(Th,“/tmp/Th.mesh”);

3

Thank you, professor :face_holding_back_tears:

4

Interesting question. Just in case, here is another mesh with one single tetrahedron

load "msh3"

{
  ofstream meshfile("test_onetet.mesh");
  meshfile<<"MeshVersionFormatted 1"<<endl;
  meshfile<<""<<endl;
  meshfile<<"Dimension 3"<<endl;
  meshfile<<""<<endl;
  meshfile<<"Vertices"<<endl;
  meshfile<<"4"<<endl;
  meshfile<<"0 0 0 1"<<endl;
  meshfile<<"1 0 0 1"<<endl;
  meshfile<<"0 1 0 1"<<endl;
  meshfile<<"0 0 1 1"<<endl;
  meshfile<<""<<endl;
  meshfile<<"Tetrahedra"<<endl;
  meshfile<<"1"<<endl;
  meshfile<<"1 2 3 4 0"<<endl;
  meshfile<<""<<endl;
  meshfile<<"Triangles"<<endl;
  meshfile<<"4"<<endl;
  meshfile<<"1 2 4 1"<<endl;
  meshfile<<"1 2 3 1"<<endl;
  meshfile<<"1 3 4 1"<<endl;
  meshfile<<"2 3 4 1"<<endl;
  meshfile<<""<<endl;
  meshfile<<"End"<<endl;
}

mesh3 Th=readmesh3("test_onetet.mesh");
plot(Th,cmm="Th");

https://www.ljll.fr/lehyaric/ffcs/src/ffref/Basic/onetet.m4.htm