Make a turret just shooting at bases

[Raelf]

Hello,

I would like to make a turret that shoots just on bases.

Why do I want that:
At the moment I play on a death world and I want to have my outpost surrounded by biters. That means they should be as close as possible so I don't want to use the Artillery Turrets here. With the current turrets I have the problem that it would be possible that biters are going to expand next to my outpost, outside the range of my turrets, but inside the range of Behemoth Worms. That means they are going to destroy my base if I'm not cleaning them regularly.

My Idea was to add a new short version of the Artillery Turret with a range just slightly higher than the one of the Behemoth Worms.
But this means also that the range will be extended when I research the Artillery Shell Range. But I want to have a fix version to have the biters always close.

Then my Idea was to make a normal turret and use shells as ammo and extend the range. But then the turret also shoots at normal biters, but I want it just to shoot at bases else the damage would be to powerful or just wasted. I was looking a bit in the API and I found I could define a EntityPrototypeFlag for the ammo. But there is nothing that defines just enemy bases and I'm also not sure if that means that the damage is limited or also the shooting.

Is there any way to make an Artillery Turret without having the benefit of the Artillery Shell Range research?
Or can I limit the normal turrets to only shoot at bases?

Thanks for your help.

[Deadlock989]

Is there any way to make an Artillery Turret without having the benefit of the Artillery Shell Range research?

I don't believe so, artillery turrets are a special case of turret, and the artillery research effects don't have a parameter where you can list affected entities like the other kinds of turret research do. So it's an assumption in the game engine that there is only one kind of very-long-range boom tube.

Or can I limit the normal turrets to only shoot at bases?

I don't think this is possible without causing a bunch of gameplay issues. Entities that can select targets and attack them will attack anything on any enemy force. You might be able to set up some shenanigans where you have a separate force for the biter entities you don't want to be shot at, e.g. you could have spawners from enemy force A produce biters from enemy force B. But I don't think that gets you anywhere, because the only way to stop a turret from firing at entities from force B and but still attack force A is to make force B neutral/friendly/allied with the player force, which means that nothing will attack them and even your own hand-weapons won't consider them to be enemies. So you'd have to look at having multiple forces for the player team as well, and mess around with changing force ownership on building new turrets, but to be honest I think this will be messy and annoying and not worth the effort. It would be a nightmare to arrange even for single player, let alone the mess of multi-force multi-player scenarios.

However, I'm not sure why you even want this - artillery only targets spawners and worms anyway, not mobile units.