Compound Surface
SetFactory("OpenCASCADE");
General.Trackball=1;
Point(1)={0,0,0};
Point(2)={1,0,0};
Point(3)={1,1,0};
Point(4)={0,1,0};
Point(5)={-1,0,0};
Point(6)={-1,1,0};
Line(1)={1,2};
Line(2)={2,3};
Line(3)={3,4};
Line(4)={4,1};
Line(5)={1,5};
Line(6)={5,6};
Line(7)={6,4};
cl=newcl;
Curve Loop(cl)={1,2,3,4};
s1=news;
Plane Surface(s1)={cl};
cl=newcl;
Curve Loop(cl)={4,5,6,7};
s2=news;
Plane Surface(s2)={cl};
Compound Surface {s1,s2};
h=0.2;
MeshSize{:}=h;
Mesh.MeshSizeMin = h;
Mesh.MeshSizeMax = h;
Mesh.MeshSizeFromPoints = 1;
Mesh.MeshSizeFromCurvature = 0;
Mesh.MeshSizeExtendFromBoundary=1;
What I am doing wrong? (Windows'10, Gmsh 4.10.5)
Edited by Michael Ermakov