Factorio Forums

A glitch I've noticed is when placing concrete on the threshold between one terrain type and another, the terrain can be changed. It can also be changed when removing said concrete. and the glitch also happens when putting down stone brick paths. The converted terrain seems to only extend along the edge of the threshold and doesn't go deeper than a couple tiles.

Here are a couple screenshots:

http://i.imgur.com/uetEgJv.jpg



http://i.imgur.com/X3yf0Zd.jpg

Related Bug Report: Re: [0.12.2]biome borders keep refreshing border tiles

kovarex wrote:The problem you are experiencing is caused by the tile-fixup logic. Basically, to avoid non-allowed tile combinations, like 1-tile wide water canal etc, the game fixes the tiles after any change. (This also chooses the 2X2 or 4X4 tiles to be used if the area is big enough).

The problem is, that you are changing tiles one by one, which is not only much slower, but also can do various results as the tile correction is done after every change.

The proper way is to save all the tiles you want to change into an array, and then do it by single call of the set_tiles method.

The solution given only applies to mods that do this in code, but putting down / removing concrete (with bots for example) calls this function one tile at a time and leads to this behavior.
The easiest way to demonstrate this is to lay down a concrete blueprint with bots over a small patch of a different biome and then remove it again. The resulting patch will look different (and repetitive).

In my case I was putting down concrete in a 10x10 area just running side to side between a couple lakes and the terrain shifting stuff happened while doing that.

I'm not using any mods.

This is the problem of the tile fix-up logic. It is doing strange things sometimes, but usually not so strange.

If you give me reproducible scenario I can take a look, as it worked properly for me when I tried it.

The scenario I found was when laying concrete in 10x10 chunks, going from one terrain type to the next would sometimes cause it. One of the odd things I just noticed is the terrain seems to be changed in 2x2 chunks. It doesn't seem to be aligned with the railroadgrid for what it's worth.

I've uploaded the save file I first noticed this with. The character has a full inventory of concrete and is standing right next to some modified terrain, and the terrain can continue to be modified. The way I've gone about laying concrete down is starting with a 10x10 chunk and just running along in the middle. The terrain conversion happens when you start on one terrain part and run along into a different terrain then keep going. Just now I've done some fiddling and at first it didn't look like laying smaller chunks caused the issue, but then I went across a threshold with a 6x6 chunk and got the terrain to follow along the front edge of where I was moving instead of along the side.

Right where the character is standing, I can start on a 10x10 concrete chunk and lay it down while running right and the bottom terrain in the corner between the old concrete and the newly laid one will always get converted from desert into wetland or whatever terrain. The top part won't go along the edge unless I center the 10x10 chunk on top of the player character or to the right of them. Starting on the left will still give the terrain change in the bottom right corner, but it won't give the terrain change on the top side while running along.

Edit: Okay, I am using a mod called Warehousing but I have tested without it and the terrain behaves exactly the same way.

I have made a video showing a little bit of this glitch in action.

https://www.youtube.com/watch?v=t1c2W8Kuyqc

Devs, if you'd like me to do more with it and have instructions I'd be happy to go through it again.

Thank you for the report. I know that the terrain fixing code has it quirks, but as it is not game balancing, I'm going to put it to minor issues.

Just want to highlight that despite (what I understand) significant changes to terrain and terrain generation, this bug is still present in 0.15.20. I haven't found exactly what triggers it but behaviour is consistent. The screenshot shows that 1 row of my concrete triggers the bug, the other one does not. I've tested at various latitudes in the vicinity but this is the only spot where the effect showed up. In all cases I dragged concrete 1 tile with running east to west.

I do have a save to replicate the issue where character stands just before applying concrete. It is however 60MB as I'm now at -22000, 0. Please let me know if you'd like this save for future reference or if I can delete it.

B4SK3 wrote:Just want to highlight that despite (what I understand) significant changes to terrain and terrain generation, this bug is still present in 0.15.20.

That would be because we never changed anything in the tile correction logic which is what's responsible for making transitions between tile types look "good" The system used to pick the type of tiles during chunk generation was changed a few times in the last major versions but as far as I can recall we haven't changed the tile correction logic in at least 3 years.

Fair enough. Thanks for the clarification. Are you interested in a save to easily replicate the issue or is it not worth spamming the forum with 60MB of save file?

So this was probably fixed with the new transitions