TomOrr0W
Assigned
Reported
Comments
I also noticed this behavior in my world after upgrading from 1.17.1 to the 1.18 release. Passive mobs in newly generated chunks that are subject to blending (i.e. near 0,0) and in deleted terrain traveled to via Nether portal seem to generate according to a different terrain configuration and then fall onto the actual terrain (be it water or land). Once I go a significant distance away from 1.17.1 chunks, mob generation in new chunks returns to normal.
Note that I deleted chunks that weren't being actively used using NBT explorer and/or deleting region files before upgrading. The linked backup is from right before the 1.18 upgrade. Also note that I ran "Optimize World" with Erase Cached Data checked before opening in 1.18. I used the following view distance settings: Render Distance: 20 chunks; Simulation Distance: 12 chunks; Entity Distance: 500%
https://drive.google.com/file/d/1MiJmn2ox4Y5Vt54P4I50y4AZJr00FjEq/view?usp=sharing
The screenshot below is an example of the issue. There is a Nether portal nearby that leads to a network of portals, some of which had the other side of the portal deleted and others which kept a few overworld chunks around the portal exit. I saw this kind of behavior in both cases.
Here is a twitch clip that appears to match this report:
Looking back at this, I had only deleted chunk data itself in my previous comment - not POI data or entity data. That was almost certainly the cause of what I mentioned in my comment - so nothing useful for Mojang there. I have not seen similar behavior in subsequent upgrades/trims where I deleted the chunk, POI, and entity data in sync.
My world hasn't been in any snapshot versions since maybe single digit full release versions or beta 1.7/1.8, so I can't answer the question by Jiingy - that would have to be up to Alejandro.