Detection mode `ABOVE_CUT` not behaving as explained in the wiki

[Narcifal]

Describe the bug

Some trees don't break as intended, leaving branches or leaves unbroken. WWOO, Regions Unexplored, etc. were used during testing. This doesn't apply only to big trees, but also to trees that are wide.

Isolated reproduction

No

Minecraft version

1.20.1

Loader used

Forge

Loader version (Fabric/Forge/NeoForge)

47.4.0

Mod version

4.3.4

Minecraft environment

Single player

Configuration

{
  "trees": {
    "allowedLogs": [
      "minecraft:mushroom_stem"
    ],
    "deniedLogs": [],
    "allowedLeaves": [
      "biomesoplenty:glowshroom_block"
    ],
    "allowedNonDecayLeaves": [],
    "deniedLeaves": [],
    "breakMode": "FALL_BLOCK",
    "detectionMode": "ABOVE_CUT",
    "maxScanSize": 500,
    "maxSize": 320,
    "maxLeafDistanceFromLog": 15,
    "maxSizeAction": "ABORT",
    "breakOrder": "LOWEST_FIRST",
    "minimumLeavesAroundRequired": 1,
    "includePersistentLeavesInRequiredCount": true,
    "treeBreaking": true,
    "leavesBreaking": true,
    "leavesBreakingForceRadius": 0,
    "allowMixedLogs": false,
    "breakNetherTreeWarts": true,
    "breakMangroveRoots": true,
    "searchAreaRadius": -1,
    "allowedAdjacentBlocks": [],
    "adjacentStopMode": "STOP_ALL"
  },
  "tools": {
    "allowed": [],
    "denied": [],
    "preserve": true,
    "ignoreTools": true,
    "damageMultiplicand": 1.0,
    "damageRounding": "ROUND_DOWN",
    "speedMultiplicand": 0.6,
    "forceToolUsage": false
  },
  "player": {
    "allowedTags": []
  },
  "enchantment": {
    "registerEnchant": false,
    "registerSpecificEnchant": false,
    "hideEnchant": false,
    "requireEnchantment": false
  },
  "sneakMode": "IGNORE",
  "breakInCreative": true,
  "lootInCreative": false,
  "notificationMode": "NONE"
}

Relevant log output

[Rakambda]

Picture 1 : do not use "breakMode": "FALL_BLOCK" if you don't want this. With big trees the blocks are basically falling on the blocks that were under (like the leaves that haven't decayed yet). I'm pretty sure if you use instantaneous this won't happen (to test).

Picture 2 : Seems more like a mushroom. In this case the "head" part doesn't decay automatically by itself. You'll have to register those blocks as "leaves need breaking" in the options.

[Narcifal]

Picture 1 : do not use "breakMode": "FALL_BLOCK" if you don't want this. With big trees the blocks are basically falling on the blocks that were under (like the leaves that haven't decayed yet). I'm pretty sure if you use instantaneous this won't happen (to test).

Picture 2 : Seems more like a mushroom. In this case the "head" part doesn't decay automatically by itself. You'll have to register those blocks as "leaves need breaking" in the options.

Regarding mushrooms, I have registered both stems and caps. I attached my configuration. We can clearly see it works like with trees: it cut a tree with a 5-block width but left everything else untouched.

As for the "FALL_BLOCK" behavior, I do want this effect, but using the instantaneous mode doesn't solve the problem — neighboring blocks still float in the air.

Here are some tests (instantaneous mode) with a rather complex tree:

In this scenario, the tree detection only cut a width of 3, leaving the rest untouched, even though it was essentially the same branch.

[Rakambda]

For the mushroom : Yes you registered it, but in the wrong category. You need to register it in allowedNonDecayLeaves (as it's not a leaf that decay, i.e. it'll be broken) instead of allowedLeaves.

For the complex tree : Can you give me a biome where these are generated so that I can take a closer look at it ?

[Narcifal]

For the mushroom : Yes you registered it, but in the wrong category. You need to register it in allowedNonDecayLeaves (as it's not a leaf that decay, i.e. it'll be broken) instead of allowedLeaves.

If we look at the picture, we can see that all mushroom leaves within a 5-block radius behave as expected (FALL_BLOCK).

Here is a closer look:

It works the same when registered with both allowedLeaves and allowedNonDecayLeaves.

The name of the biome is biomesoplenty:glowing_grotto

[Narcifal]

For the mushroom : Yes you registered it, but in the wrong category. You need to register it in allowedNonDecayLeaves (as it's not a leaf that decay, i.e. it'll be broken) instead of allowedLeaves.

For the complex tree : Can you give me a biome where these are generated so that I can take a closer look at it ?

I think the best biomes to test this are minecraft:old_growth_spruce_taiga and minecraft:meadow using WWOO. There are also various trees from Oh The Biomes We've Gone, Biomes O' Plenty (for example, biomesoplenty:glowing_grotto), and Regions Unexplored, where the tree detection behaves the same way.

[Rakambda]

Ok found some that have that behavior. Those trees don't have trunks that are made of just logs. Exemple, some are made of minecraft:oak_log + minecraft:oak_wood.

You'll have to set the config allowMixedLogs to true.

---

So if we sum up all the different points that were all mixed up

• For the trees : set allowMixedLogs to true as they have mixed blocked trunks.
• For the breaking mode : INSTANTANEOUS should work best to destroy it all. If you prefer FALL_BLOCKS it's up to you, it should break things properly with the previous point. Just be aware that this mode is purely made to be "visual" and may have weird behaviours.
• For the mushrooms : register "leaves" that don't decay by themselves in allowedNonDecayLeaves instead of allowedLeaves.

[Narcifal]

Ok found some that have that behavior. Those trees don't have trunks that are made of just logs. Exemple, some are made of minecraft:oak_log + minecraft:oak_wood.

You'll have to set the config allowMixedLogs to true.

So if we sum up all the different points that were all mixed up

• For the trees : set allowMixedLogs to true as they have mixed blocked trunks.
• For the breaking mode : INSTANTANEOUS should work best to destroy it all. If you prefer FALL_BLOCKS it's up to you, it should break things properly with the previous point. Just be aware that this mode is purely made to be "visual" and may have weird behaviours.
• For the mushrooms : register "leaves" that don't decay by themselves in allowedNonDecayLeaves instead of allowedLeaves.

Regarding big spruce trees in the old_growth_spruce_taiga biome, the allowMixedLogs option didn’t solve the issue because the logs are not actually mixed. (INSTANTANEOUS mode was used for the latest testing)

[Rakambda]

Okay, seems to be a bug with detectionMode: ABOVE_CUT, never behaved as it should. Basically it acts like a "always branch up, never down".

I'll fix that. However it'll be only part of the last release. 1.20.1 is way too old I won't backport it. You can use the ABOVE_Y, should be close enough enough to what you want, or WHOLE_TREE.

[Rakambda]

Actually I'm not too sure how to fix it. I think I did that to avoid 4x4 trunks to have a weird behavior (as it could just loop around the starting log). I guess i'll just keep the current behavior and make the wiki reflect the actual behavior.

And ABOVE_Y will be a more suitable case to break things above a certain point (usually players hit the log, so it should go straight up).

[Narcifal]

Yeah, I can see the issue: selecting 'ABOVE_Y' solves the previous problem but creates a new one—several nearby trees are broken instead of just one. In a denser forest, that becomes a problem.

[Rakambda]

Yeah it's rather common problem. Either we allow more shape of threes, but this also means dense forests suffer from it. Or we are more strict but some trees get broken down into several parts.

What you may try with ABOVE_Y is to lower the value of maxLeafDistanceFromLog this should lower the size of the "bush" taken into consideration. Like maybe set it to 1 or even 0.