Factorio Forums

Video: https://youtu.be/5_58fTmdE2c
Savegame in attachment

Loewchen wrote: Tue Feb 18, 2020 10:47 pm viewtopic.php?f=48&t=74947

Nope, this is not the exact same, since the same blueprint has inconsistant behavior of the inserter even within the exact same layout AND is changes default behavior when mirroring
See: https://i.imgur.com/k5AzUfW.jpg

Also I show a situation here where an inserter grabs from the far line of a straight belt!

Taking from curves is working as intended regarding mirroring (ignoring build order shenanigans), the inserters are always taking from the left belt lane.

Taking from the far lane of a perpendicular belt is not intended afaik:


This and taking from the right lane in a curve (at the end of your video) seems to be related to build order, see this post:

Twinsen wrote: Mon Sep 02, 2019 8:54 am

foamy wrote: Fri Aug 30, 2019 11:08 pm Which lane the inserters pull from can be influenced by construction order. Since this is now inconsistent behaviour I think I'm safe in saying it is not only unintended, but a genuine bug.

Ugh.
Can you make a detailed report about it? We might still consider it a minor issue but if i have some detailed steps i'll take a look at it.

So I am moving this out of duplicates.

Bilka wrote: Wed Feb 19, 2020 10:05 am Taking from curves is working as intended regarding mirroring (ignoring build order shenanigans), the inserters are always taking from the left belt lane.

Taking from the far lane of a perpendicular belt is not intended afaik:


This and taking from the right lane in a curve (at the end of your video) seems to be related to build order, see this post:

Twinsen wrote: Mon Sep 02, 2019 8:54 am

foamy wrote: Fri Aug 30, 2019 11:08 pm Which lane the inserters pull from can be influenced by construction order. Since this is now inconsistent behaviour I think I'm safe in saying it is not only unintended, but a genuine bug.

Ugh.
Can you make a detailed report about it? We might still consider it a minor issue but if i have some detailed steps i'll take a look at it.

So I am moving this out of duplicates.

Can you show two identical looking cases where the inserter takes from different sides next to each other?

mrvn wrote: Wed Feb 19, 2020 11:02 am Can you show two identical looking cases where the inserter takes from different sides next to each other?

Sure. Start state is setup without build order manipulation and all inserters picking up correctly. End state is left side inserters picking up incorrectly after build order manipulation.

This isn't really worth our time looking into, and doesn't significantly affect the gameplay

to me, this looks somewhat related to something i read and learned about "cars on belts" some time ago.
there, i read that inserters "lock" to where they grab items from (from belt vs from cars).
nonetheless, in some cases (edge cases "only" ?) this is inconsistent behavior when apparently randomly the inserter will lock to the near side / outer side of the belt, OR to the far side / inner side. such layouts might not be very common, most people probably will have mostly "singletype belts" where it doesn't matter a lot, and won't rely on taking from a specific side first. i still could imagine just that, eg when relying on items first to be taken from one side and later filling that side by sideloading, or relying on taking items of the correct item type from a specific side of a saturated two-item-type belt. or maybe even just the opposite, (mis)using this behavior to make inserters prefer to grab from the far side or outer lane first.
TL/DR : because of the possible inconsistency in some (edge) cases and until/unless this possible inconsistency is at least documented, i consider either the game or the documentation/wiki to be slightly buggy/incomplete.

of course, take care of other more important bugs first (keep this a "minor issue" to be fixed "sometime" later), but with your record of taking care of every small detail please don't say "not worth our time" (which sounds like "no bug" or "won't ever fix") and/or fix at least the wiki, adding a hint about possible deviations from the given rules to the paragraph about "potential issues", maybe something as simple as "if inserters once take an item from one side of belts, they may stay locked to that side and not follow the above rules for a preferred side". thus people would be warned about possible problems with blueprints, and even might start using this trick to grab items from the "other" side on purpose :-)

This was fixed with the fix for 108046. The original change mentioned in that thread was adjusted so that the pickup lane without build order weirdness is the same as always, but changing the belt from curved to straight now updates the pickup lane. Moving to resolved for next release.