Ship Cannot Target Buildings

[Vectorus]

Today a ship would not fire on a military biodome - perhaps the targeting code doesn't know that certain buildings can now be military which were not before? Because all other military buildings were inside this biodome, the ship then couldn't fire on anything at all. Even in berserk posture, I think it tried to target the military buildings first.

One helpful improvement would be if ships, after unsuccessfully targeting  a given building or ship for a certain period of time (after coming to a rest, no more repositioning), moved onto the next available target in range (according to posture), eventually cycling round.

This would help all sorts of situations where an NPC crew becomes fixated on trying to destroy a currently indestructible target while ignoring dozens of perfectly vulnerable ones nearby.

Deantwo also made a good suggestion, I'll expand on it: A ship should fire even if its line of sight is obstructed. After a certain time, if it has not damaged *anything*, it should cycle to the next target (or stop if only one target remaining). If it has damaged something, even if not the intended target, it should keep firing. The only exception should be if the obstruction is an object belonging to an empire *other than the target*, i.e. you won't shoot a neutral ship to get at an enemy behind it.

[Deantwo]

Crew is currently very basic with their targeting of buildings. They only attack the nearest target, but if that one target is blocked by a hill or another building somehow, the crew won't fire at all and just sit there forever doing nothing.

I don't doubt that this is the issue with the biodome you mention. The ship is likely targeting a building in the biodome and seeing it blocked by the biodome.
You should check what happens if you manually fire at the different targets. Do they hit the biodome instead? Can you damage the biodome at all, or is there no hit confirmation?

This issue is made even worse with line of sight checks failing against buildings that are (even just kinda) behind terrain. As I have pointed out in the bug report about underground buildings.
See: (Bug report) Underground Buildings Exploits

[Vectorus]

Yes, more testing suggests the issue really is that nothing else could actually be hit while the biodome stood, but the crew was too obsessed to try killing the biodome first. The above changes would fix that.

Making the change to attempt a certain number of shots even with LoS obstructed would fix the vast majority of issues with AI being unable to hit bunkers etc, as long as they have appropriate cratering weaponry. The rest you can (in principle) deal with manually, though I have found a few bugs with cratering not working recently.