Thanks. I got it.
But I have another question about the gate geometry.
By using the command Zmin, Zmax, etc. We can draw a rectangular gate easily. However, that also means the sides of the gate should be aligned with the x(or y,z) direction. If it possible to have a rectangular gate with side in any direction (for example align with the line that is (for example 45 degree) between the y,z axis in the yz plane).
Thanks in advance and looking forward to your reply.