Could you please help with the following:
<< NDSolve`FEM`
a = 0.1;
b = 0.05;
chi = RegionUnion[Rectangle[{-a, -b}, {a, b}], Rectangle[{-b, -a}, {b, a}]];
DiscretizeRegion[chi];
Omega = RegionDifference[Rectangle[{-1, -1}, {1, 1}], chi];
DiscretizeRegion[Omega]
ToElementMesh[Omega]["Wireframe"]
DiscretizeRegion[] works as expected, but ToElementMesh[] produces an unexpected result. What could be the difference?
My outputs are as follows: