Mirroring at the point of origin (0/0/0) means that the sign of all coordinates is changed. So a minus in front of the whole vector is enough for this.
Could you make me a "lantern" as a gift, say: 8 different color on 8 "structure". ( I'm going to choose and buy a lantern for my grandchild tomorrow, for Mid-autumn Festival in Asia ) Best Regards. Loi.
You may be interested to hear that you can let Mathcad create the necessary structure for the first lantern segment using the parameter representation of a sphere and the function CreateMesh. And, no, you cant evaluate the result symbolically, only numerically.
You may also add sort of a scaling-factor in z-direction