[miraboreasu]

This is for Gmsh
Hello
I have a sphere inside a box with a radius equal to 0.05 and make a physical surface

```
SetFactory("OpenCASCADE");
Block(1) = {0, 0, 0, 5, 5, 5};
Sphere(2) = {2.5, 2.5, 2.5, 0.05};
BooleanDifference(3) = { Volume{1}; Delete; }{ Volume{2}; Delete; };

inner() = Surface In BoundingBox{2.449,2.449,2.449, 2.551, 2.551, 2.551};

Physical Volume("my volume") = {3};
Physical Surface("my inner surface") = inner();

Mesh.MeshSizeFromCurvature = 30;
Mesh.MeshSizeMax = 0.2;
```

Now I want to keep the same box, and the same center(2.5), but make this sphere into an ellipsoid, which has a larger c in the picture (looks like a shuttle), values of a, b, and c are in the picture. I also need a physical surface for this ellipsoid.
I searched online, but didn't find a good solution, can anyone help me? I prefer using OpenCASCADE, thanks!