Nether forest biomes: Large fungi and small plants only generate on the topmost layer of nylium, leaving all lower layers devoid of flora

I'm shocked no one has been assigned this yet

Can confirm for 1.16 Pre-release 5

I still really hope there is time to fix this before release

Can confirm for 1.16 Pre-release 6

Can confirm for 1.16 Pre-release 7

This seriously needs to be fixed.

Hopefully this gets fixed before 1.16 gets fully released.

Can confirm! Still happening in 1.16 Pre-release 7 (16. 6. 2020). One of the biggest bugs still needs to be fixed before official release!

This bug really, really, REALLY needs to be fixed before 1.16 is released!

Is this still an issue in pre-release 8?

@unknown please check the affects version. I have already confirmed this for 1.16 Pre-release 8, and updated the ticket accordingly.

Still present in 1.16 release candidate 1

is this actually going to be fixed or will we be forced to wait until a later version of the full release....

@@unknown -> It is likely not to be fixed by 1.16 release, fixing this bug will probably break terrain generation on nether/overworld as trees and terrain decoration works the same on both dimensions

The generator starts looking for a first surface block from 255 down to put the features, give us a parameter to change the 255 to whatever in our custom dimensions so we can have the features in the first surface block from that value down. That would be a good fix.

The value would default to 255 and we could change it.

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Hi, a solution for this bug can be to stick all of the valid positions into a list and then pick a position from the list using the random given to the feature. This is the code for the nylium tree Feature (HugeFungusFeature) now: 

private static BlockPos.MutableBlockPos findOnNyliumPosition(LevelAccessor level, BlockPos pos, Block targetBlock) {
    MutableBlockPos mutable = pos.mutable();

    for(int i = pos.getY(); i >= 1; --i) {
        mutable.setY(i);
        Block currentBlock = level.getBlockState(mutable.down()).getBlock();
        if (currentBlock == targetBlock) {
            return mutable;
        }
    }

    return null;
}

As you can see, once it finds the topmost block, it returns. Using the list based code to prevent that, it would look like this:

private static BlockPos.MutableBlockPos getStartPos(LevelAccessor level, Random random, BlockPos pos, Block targetBlock) {
    List<BlockPos.MutableBlockPos> positions = new ArrayList<>();

    BlockPos.MutableBlockPos mutable = pos.mutable();
    for(int i = pos.getY(); i >= 1; --i) {
        mutable.setY(i);
        Block currentBlock = level.getBlockState(mutable.down()).getBlock();
        if (currentBlock == targetBlock) {
            positions.add(mutable.mutable());
        }
    }

    if (positions.size() == 0) {
        return null;
    }
    return positions.get(random.nextInt(positions.size()));
}

You guys can do whatever you please with this; it's CC0.

Unfortunately this does come with a few caveats, as it will reduce the density of trees in a chunk by half as it now attempts to generate on all surfaces instead of the topmost surface, and it will break world generation as it uses the Feature random to select a random surface to generate on. A smarter solution may be to create a new Decorator to select 8 surfaces to plant on instead of doing it in the Feature.

Here it that code in action:

Can't belive this was reported 4 months ago and they still havent done a thing about it
They just set it to "Important" and forgot about it
Yet when there is a world gen bug in the Bedrock Edition (no basalt/sould sand on the ceiling) they are rushing to fix it asap

@Alek Duchacz as Sliced Lime said a bit of time ago, fixing this require changing something that is very sensitive in terms of coding it it can break too many things to be fixed asap. Java team also try to fix generation bugs as fast as they're able. It's just a very difficult one. Also this mechanic in this form is present in the game since it's very beggining, so just imagine how much of a sphagetti it is. Since the very first days of "decoration" mechanics they generated only on topmost layer that had only sky above (buffet caves doesn't have trees and most of the structures below bedrock at all). The only thing that they changed for now is that "decorations" can generate without having only air above. Fixing this before full 1.16 would make most of the snapshots VERY unstable and would even delay release for few weeks.

Also if I'm correct, it's present in bedrock edition too. At least with basalt remnants.

I believe it's called decorations, but I'm not sure if I didn't mistake it with the other mechanics.

@Devu
Wait so the buffet caves actually have trees in the Bedrock Edition?
Neat

@Alek Duchacz Bedrock Edition doesn't have buffet type at all

got fixed in 20w08a