Those aren't coordinates... they're distance parameters. They say how far away from the coordinates you set particles can be generated. So if you remove the tildas, it will generate particles in a 3*3*3 circle around those coordinates. And they can't be negative, either.
Those aren't coordinates... they're distance parameters. They say how far away from the coordinates you set particles can be generated. So if you remove the tildas, it will generate particles in a 3*3*3 circle around those coordinates. And they can't be negative, either.