When you create a zone, is the zone spherical or can you set it up to be a flat / rectangular zone?
Example, I want all my asteroids to spawn in a 40km upwards and 40km downwards zone covering my whole system making a ring of asteroids 80km in total in thickness around 0, 0, 0

dont worry, got there in the end, to anyone else struggling needs filter api mod aswell and the radius isn't the radius its diameter so for 10000km the 'r' needs to be 20000000

how would i create a zone so asteroids only spawn between 10000km and 12000km from X0,Y0,Z0 ?

Fantastic, just what I needed, was worried I need to create my own mod using your API to just spawn asteroids only in a radius from 0,0,0 and not into infinity. Thank you!