[posila] [1.1.21] Wall ghosts increase size of tree/rock they are placed on

[Lancefighter]

I ran into a small bug using repair turrets - https://mods.factorio.com/mod/Repair_Tu ... e82b3db34e

It turns out, this is a vanilla issue. A wall blueprint on a tree or a rock has a large collision box, preventing placement of other walls next to the blueprint.

This picture mostly demonstrates it https://cdn.discordapp.com/attachments/ ... nknown.png You can place the wall before placing the ghost, but once you place the ghost, you cannot place more walls adjacent to that ghost, even if they otherwise wouldve been place able.

This is kinda a nonissue edge case, though it is reproducible easily. Robots that do not have enough range to deconstruct the rock/tree in question will just idle above the expected spot, hoping one day the placement will become valid https://cdn.discordapp.com/attachments/ ... nknown.png

I dunno how else to say stuff here. Thanks to Mekasha in Earendel's discord for helping me figure out the root cause of the issue.

[posila]

Thanks for the report.
I don't think this is a bug, but will move it to minor issues, since it might be confusing behavior and also seems to depend on order in which things are placed.
Yes, walls and pipes extend their bounding box to the edge of the tile with neighbouring wall/pipe to create tight seal.

[Lancefighter]

Id generally agree, but is it intended for the ghost to be increasing collision size, and not the actual built wall itself?

Id agree its a general nonissue, but due to some weird priorities it is causing issue with limited scenarios where items are trying to be placed and fail in specific orders.

[posila]

I looked at the save you shared in the report on mod portal, and that case looks more broken than the screenshots you posted here ... I think it has something to do with prevention of players walling in themself... which was not really a bug, but people kept reporting it, so kovarex fixed it anyway.

[posila]

Good news is, I fixed the issue of walls not being placable on valid positions next to ghosts that collide with entities marked for deconstruction.
Thanks for the report.
Fixed for 1.1.22.

Bad news is, this still doesn't fix the issue of repair turret burning through all the wall items trying to rebuild a wall that it can't. Problem is the buildability check it does passes, because there is already wall ghost on that position, which connects to the neighbours and a dummy wall the buildability check uses can't connect to them anymore, so it doesn't check with its real final bounding box. But then ghost revive fails due to the revieved wall really colliding with the tree.

The proper fix would be to make sure the buildability check works the same way regardless of ghost being there (so the dummy wall must connect to walls/ghosts that are already connected to the ghost), but that seems as quite challenging change. I'll see if I can think of something.

[Lancefighter]

It was hard to convey what was specifically the repair turret's fault or base games fault, so I erred on the side of reporting what I could figure out in vanilla only. After all, the construction robot seemed happy to idle above the wall ghost, so I didnt initially consider the item destruction to be an important part of the core issue.

Thankfully, it seems you have a good idea of whats going on here, and my stone supply will thank you for preventing too much intended strain on wall construction.