The bug
When trees, kelp, bamboo, and huge mushrooms generate near biome boundaries, they will generate rough edges on chunk boundaries instead of generating together with the other plants near the biome boundary. Kelp and bamboo will also generate strictly within chunks, inside their respective biomes. Some other plants will only attempt to spawn in certain chunks, but they can still spread out of the chunk (which might also be a bug). This can cause ugly world generation on biome boundaries, including odd bee nest and large tree distribution, and patches of jungle that lack trees near a river.
How to reproduce
Use the seed 5878760421836343227 and teleport to 702 82 652 to go to a river that caused patchy plant generation in a bamboo jungle (and a lot of them nearby).
Related issues
is duplicated by
Attachments
Comments
migrated
seeker3000
This may be connected to MC-125007
gaspoweredpick
Added more screenshots since this happens pretty much everywhere.
gaspoweredpick
Added even more screenshots of patchy biome generation. The biome intersections in look blatantly wrong even without chunk boundaries shown!
qwerty23495
You might be referring to MC-131808
gaspoweredpick
This bug may not be fixed in 19w41a, but tree generation seems to not be completely based on the chunk boundary anymore. Kelp generation also makes a bit more sense similar to Bedrock edition. My current seed to reproduce this bug no longer causes a treeless hill. The developers may not have completely fixed this bug, but they definitely fixed something that's up with the patchy world gen.
I may make a new seed to reproduce this if 1.15 (pre release) is out and this bug report is still not acknowledged by the devs. Keep in note that plant distribution has changed for 19w41a and later.
Adrian Östergård
We can't reproduce with the reproduction steps provided. If it's still an issue, please provide seed and coordinates for where it happens.
gaspoweredpick
Try using the seed -768058393200282115 and teleporting to 3400 65 -3176. You can see that rivers in jungles cause rough edges between the jungle "chunks" and the river "chunk". There are a lot of them near this river as well.
migrated
Thanks. I can reproduce this now.
[media]
migrated
It seems that the generator chooses a "main" biome in each chunk, and only generates the features of that one.
In this example you can see a lot of patches with the dark forest biome that have no trees, and all of them are in their own chunk.
Seed: -8754354938067898153
Coordinates: /tp 4025 130 4810[media]
Edit: It can also be seen in the Nether. Notice how you can't find both a warped and a crimson fungi that start in the same chunk (from the stem, or the middle stem for large fungi).
gaspoweredpick