The Bug
Just before 21w43a came out, the snapshot where terrain blending is added, I posted a feedback about 21w42a that mojang has already applied chunk blending for 1.17 worlds on trees, corals, and structures. The next day, I checked the newest snapshot. I recovered my 1.17 world and opened it in the snapshot to see how the chunk blending is applied, and discovered trees are split in half again. It mainly happens when the 1.17 biome is dark forest. I can confirm this bug for 21w44a and 1.18 Pre-release 1. On the bottom left of the photo you can see the version of the world.
Reproduce
Create a world in 1.17.1 or lower
Go to a biome with trees
Close and open the world in 1.18 pre-release 1 or higher
Go towards the new chunks
Observed Result
The trees were cut in half
Expected Result
The trees would not get cut in half
Linked issues
is duplicated by 2
relates to 2
Attachments
Comments 15
Please supply your un-upgraded world and coords, if possible. This will help speed along the process.
It is unfortunately not possible to share files bigger than 10MB. The world is 32MB. But as I said, it happens mainly on dark forests. It doesn't happen on for example taiga.
@Bug bug it doesn't. The bug is caused by the way how tree generation changed from the newest update. On 1.17 it generated dependend on the seed. In the newest update it generates randomly. So the only way to fix this bug I think would be to implement a bit of the old generation inside 1.18's code.
I wonder if people would still notice this bug since everyone updated their world already. They might save this bug for when the next world generation update is coming and this biome blending is applied to that.
Can the title be changed to something like:
"Trees can be cut off at new chunk boundries when upgrading a world to caves and cliffs world generation"
Chunk blending for trees was never actually a thing. When the tree generates in the newer chunk, it spreads to the old chunk, but when the tree generates in the old chunk, it doesn't spread to the new chunk. I can however confirm for 1.18 Pre-1. Relates to MC-125007