[Qiyue]

Hello,
I am trying to generate a sphere with version 4.10.3 Gmsh, and two method are used:
1) to use the 'Sphere' command:

SetFactory("OpenCASCADE");
//+ This is to set the background mesh size.
//+ Check t10.geo for more information.
lc = 0.04;
Field[1] = Box;
Field[1].VIn = lc / 2;
Field[1].VOut = lc / 1;
Field[1].XMin = -0.1;
Field[1].XMax = 0.1;
Field[1].YMin = -0.1;
Field[1].YMax = 0.1;
Field[1].ZMin = -0.1;
Field[1].ZMax = 0.1;
Background Field = 1;
Sphere(1) = {0, 0, 0, 0.1, -Pi/2, Pi/2, 2*Pi};
//+
Surface Loop(1) = {1};
//+
Volume(1) = {1};
//+ This command makes all surface meshes pointing to the outward.
ReorientMesh Volume {1};

2) to use the 'circle arc' then extrude/rotate

SetFactory("OpenCASCADE");
//+ This is to set the background mesh size.
//+ Check t10.geo for more information.
lc = 0.04;
//+
Point(1) = {0, 0, 0, lc};
Point(2) = {0, 0.05, 0, lc};
Point(3) = {0, -0.05, 0, lc};
//+
Circle(1) = {2, 1, 3};
//+
Extrude {{0, 1, 0}, {0, 0, 0}, 2*Pi} {
Curve{1};
}



Both methods generate two unknown entities (curves) at the ends of circle arc.
Could anyone show some clues that how these unknown entities come out and how to eliminate them? Appreciate your feedback

Qiyue