Working on Z coordinates

Based on this OLC.
I still need to have the user click on a star and make that the center of things!
The z coordinate of the star allows you to move in three dimensions.
I want make a solar system..

# Stars: 17
GalX: 5911, GalY: 43002, GalZ: 729
My pseudo random numbers are pretty average: 0.49187891378047766
x: 0 y: 0
260, 260
Star: -1, mass: undefined, luminosity: undefined

Oops!