@david-arthur, on 21 March 2011 - 01:39 PM, said in Disappearing spobs:
It actually works by hiding and showing the entire system.
Each system has a field called 'Visibility', which allows to set whether the system is shown by reference to control bits. If your system's visibility is '!b123', it will disappear as soon as bit 123 is set, whether by a mission, a crön, or various other effects. If you have another system with the same location and name whose visibility is 'b123', it will appear at the same time, and from the player's point of view one of them has replaced the other.
Once you've created your two (or more) systems, you then have the choice of whether the replacement system contains the same spöbs, leaves some of them out, adds some, or again uses new spöbs with the same name so that the player thinks that some aspect of the planet has changed. If, for example, you had a mission that ended with the bar on Port Kane being destroyed, you would replaced Kania with an almost-identical system containing a spöb that was identical apart from there being no bar.
Of course you're also allowed to have a system appear or disappear part way through the story without replacing or being replaced by another one.
Thank you very much! That was quite helpful