Flat Bedrock Mod Wiki › FAQ
Flat Bedrock Mod FAQ
10 questions players actually ask, answered.
How do I make the Bedrock flat in a world I already started?
Set retroGenTop or retroGenBottom to true in the relevant dimension's JSON file in /config/flatbedrock/dimensions/. This makes the mod re-run generation on already-loaded chunks, so existing bedrock gets flattened too.
What does genTop and genBottom actually mean?
GenBottom controls the floor layer of bedrock at the bottom of the dimension, and genTop controls the ceiling layer at the top. Set each to true for the layer you want flattened and false to leave it alone.
How do I add a new dimension to Flat Bedrock?
Create a new JSON file in /config/flatbedrock/dimensions/ named after the dimension, and set dimID to that dimension's numerical ID. Copy the structure of overworld.json or nether.json and adjust genTop, genBottom, and fillBlock as needed.
What number do I put for dimID?
DimID is the numerical dimension ID, not the name — the overworld uses 1 and the nether uses its own ID in the default nether.json. Check the mod or dimension you're targeting for its registered numeric ID rather than guessing.
Can I change what block replaces the Bedrock?
Yes, change the fillBlock value in the dimension's JSON file to any valid block ID, like minecraft:stone. The mod will use that block for the flattened layer instead of bedrock.
Why isn't my flat Bedrock showing up after I edited the config?
Config changes usually require a game or world restart to take effect, and already-generated chunks won't change unless retroGen is enabled. Make sure the JSON is valid (no trailing commas) or the file will be ignored.
Does Flat Bedrock work with other dimensions from mods?
Most dimensions should work as long as you add a JSON file with the correct dimID for them. Some heavily customized dimensions may not behave as expected, so test in a copy of your world first.
Will this break my existing world or cause chunk errors?
Retro-generation rewrites bedrock in already-loaded chunks, so back up your world before enabling it. New chunks are safe since they generate with the flat layer from the start.
Does Flat Bedrock affect performance?
The mod only touches bedrock layers during generation, so ongoing performance impact is minimal. Retro-generation can cause a brief spike when chunks are first processed.
Can I flatten only the nether roof but not the floor?
Yes, set genTop to true and genBottom to false in nether.json (or vice versa) to control each layer independently. The same applies to retroGenTop and retroGenBottom for existing chunks.