Bedrock to Java Biome Conversion Question

[PardosaAtromedia]

Chunker Version

Chunker-1.15.0-windows-x86

Input World Version

Bedrock Version 1.21.130

Output World Version

Java Version 1.21.10

Platform / Operating System

Windows 11

Issue Description

When trying to convert some of my Bedrock worlds to Java I noticed that if you build above ground level in converted chunks, the biome changes to Plains regardless of the biome directly below. I am not sure if this is how the program normally works or if it is a bug. What appears to be happening is that the conversion saves the biome data in locations near blocks but uses a default plains biome in the absence of nearby blocks.

I also tested the conversion with the Prevent Y biome Blending setting both on and off.
I was wondering if there is another setting I could change or another tool that could be used to efficiently fix the biomes across the map? I know that the fill biome command could manually fix this for a specific area but it would be hard to do that for all the locations in large maps.

Some examples of what I have noticed:

As shown in the picture, when building new leaf blocks up after the chunk is converted, they change as they go up because the biome has changed.

In the Nether the biome that exists in the empty spaces far enough away from the floor and ceiling has also changed to plains.

This also happens in the End above and below the end island.

I can get more screenshots if that would be helpful.

[FormallyMyles]

Thanks for reporting this issue, we've been able to replicate it and it's something we'll improve in the next release when the "Prevent Y Biome blending" setting is enabled.

Chunker tends to convert only chunks which are present, which in the case of Bedrock -> Java doesn't include the air chunks for the rest of the column. This means Java uses the fallback of plains which is what you're seeing.

[PardosaAtromedia]

Thanks for looking into the biome conversion