Forest generation works bad in 1.18.1

[molor]

WorldEdit Version

7.2.9-SNAPSHOT+6045-3fa364b

Platform Version

git-Paper-141 (MC: 1.18.1)

Confirmations

• I am using the most recent Minecraft release.
• I am using a version of WorldEdit compatible with my Minecraft version.
• I am using the latest or recommended version of my platform software.
• I am NOT using a hybrid server, e.g. a server that combines Bukkit and Forge. Examples include Arclight, Mohist, and Cardboard.
• I am NOT using a fork of WorldEdit, such as FastAsyncWorldEdit (FAWE) or AsyncWorldEdit (AWE)

Bug Description

/forestgen generates new trees above existing ones.

Expected Behavior

Before update to 1.18.1, in version 1.17.1, it worked correctly and doesn't place dirt blocks inside leaves. I expect that in the new version it should work the same way.

Reproduction Steps

1. Go to plains;
2. Use /forestgen multiple times

Anything Else?

No response

[wizjany]

this is an issue with changes in mojang's tree generation code. unsure if this was intentional but we may have to do extra validity check that they did previously and don't now.

[DrBMello]

Hi, I was wondering if there's any work around for this issue?

[bl4ckv01d]

Me too. The command //forest works fine on flat area... but as soon as the terrain gets difference in elevation, trees start stacking on top of eachother. Super annoying to get rid of haha :D

Maybe a solution would be to only allow a tree to spawn on an existing grass_block. Without giving it permission to create one on its own. All the stacked trees have created dirt beneath them...

[0rbitL1]

this is also a problem in 1.19.2, does anyone know how to get around this?

[octylFractal]

There is no workaround AFAIK, fixing this is quite involved because the checks are no longer straightforward. I've taken multiple stabs at it without results.

[churchner420]

Same thing happening to me on the latest version on MC 1.20.2... Additionally, the trees also generate on water surfaces not just on top of each other...
From what I've seen so far in this issue tracker, the issue can't be worked out... Could you please remove it then? Forestgen completely unusable atm

[wizjany]

this was fixed by mojang in 23w14a.

ok several things were fixed there, but trees are still allowed to spawn in midair. that said, this is actually perfectly valid - most structures/features are actually allowed to spawn in midair. the restrictions of the normal world gen procedures are dictated by separate placement rules and are non-existent in the features themselves.

there's a separate registry for "placed features" which we might want to expose at some point, but that might also be more restrictive than people want, so we'd have to figure out how to allow both.

one thing i can think of in the meantime would be to add placement masks to feature brushes, etc. to tell worldedit not to attempt to place features in certain places, but it would be on the user to decide what's appropriate for the given feature.