FAQ & Issues

Here are some basic facts about biomes that may be useful when using BiomeTweaker.

FAQ

• The scripting language is very likely to contain shortcomings. Please report any bugs you find to the issue tracker.

• Script commands are run in the order you type them. If a script command comes before another one in your script file, it will be run before the other one.

• BiomeTweaker heavily uses ASM to modify the BiomeGenBase class. This is required for a few settings to be a thing. This may not work with some modded biomes if they completely override the appropriate method. Submit an issue in such cases.

• Biome IDs are always non-negative. This means if you provide a negative ID, bad things will happen (except for -1, for reasons. Still, only use non-negative ones). The IDs must be less than 256, or bad things will happen.

• BiomeTweaker generates a report on every biome on startup. You can use this to copy biome properies and check for ID conflicts.

• Minecraft keeps all registered biomes in a fixed size array (256). Even if you specify BiomeTweaker should remove a biome, it will still be present in that array. It is only removed from the BiomeManager. This causes it to not appear in world generation, but other mods can still retrieve references to it. Completely removing a biome causes bad things to happen.

• Tweaks are processed when FML indicates it has finished loading mods. This is done to ensure that all mods have registered their custom biomes, but it also means that other biome-related mods may not initially recognize biomes added through BiomeTweaker. If this is an issue for you, you can use the Tweaker object to change the application stage. See the script command reference for details.

Known Bugs & Issues

• You can't remove oceanic, edge, desert, or mutated biomes. They are hard-coded into the generation code. Replace them instead.

• Removing all biomes of a type may cause a crash. You can find biomes and their types here. If you add a biome to all generation types, you can remove everything else and avoid the crash. See the desert example script for adding a biome to all types.

• Animals and mobs won't spawn directly over water in ocean biomes even if added to the viable spawn lists. There must be at least 3 blocks between the grass and water.

• Some biomes such as mesa have hard-coded generation blocks, and changing them will cause cave, ravine, etc.. generation to derp out.

• Some biomes such as Mesa set some block's metadata, and this metadata does not go away when changing generation blocks. e.g. setting the fillerBlock to sandstone in a mesa will generation creeper-faced sandstone.

• When using BiomeTweaker with Biomes O' Plenty, make sure to read this post on mushroom biomes.