Noticed this in 1.21.1 NeoForge and Fabric. Just a heads up, you can add c tags to you has_structure tags. For example, your desert tower tag could pull in c:is_desert biome tag to spawn in modded desert biomes!

You can view all c tags here. Both NeoForge and Fabric provides these tags
https://github.com/neoforged/NeoForge/tree/1.21.1/src/generated/resources/data/c/tags/worldgen/biome

Yes, please do this! Terrralith adds a bunch of biomes and I haven't seen a single tower in the distance even with Distant Horizons. Maybe it's an issue with something else cause I can't see Waystones either so far.

Noticed this in 1.21.1 NeoForge and Fabric. Just a heads up, you can add c tags to you has_structure tags. For example, your desert tower tag could pull in c:is_desert biome tag to spawn in modded desert biomes!

You can view all c tags here. Both NeoForge and Fabric provides these tags https://github.com/neoforged/NeoForge/tree/1.21.1/src/generated/resources/data/c/tags/worldgen/biome

Hey,
would you know all variants of c tags so I can have them added for all my variants?

Check the links under the C tag section here. They link to fabric and neoforge repository where you can see all the c tags those modloaders specifies which will be the same tags for both as of 1.20.5 and newer

https://gist.github.com/TelepathicGrunt/b768ce904baa4598b21c3ca42f137f23#what-tag-entries-exist-that-i-can-use

No the individual entries would be where the required false can be. The array of entries can have an entry be a string or an object. The corrected version of your json would look like this:

{
  "replace": false,
  "values": [
    "#minecraft:is_mountain",
    "#minecraft:is_hill",
    {
      "id": "#c:is_mountain",
      "required": false
    },
    {
      "id": "#c:is_hill",
      "required": false
    }
  ]
}

@TelepathicGrunt

Would this look accurate to you?
derelict_tower.json
{
"replace": false,
"required": false,
"values": [
"#minecraft:is_mountain",
"#minecraft:is_hill",
"#c:is_mountain",
"#c:is_hill"
]
}

Completed! Got any biome from either terralith, bop, oh biomes youll go that I can test it loading with?

Not sure which biomes of these mods use which tags, so if you might know by chance, and I validate the test now, ill be able to push all version updates tonight @TelepathicGrunt @crafting-Aaron

Terralith, biomes o plenty, and biomes we’ve gone all should be using biome tags afaik. They were when I last checked

seems to have worked, spawning in crag gardens of byg

Is this worth adding in version lower than 1.21? @TelepathicGrunt I would add 1.20.1 if so

you can do 1.20.1 as well as biome mods were using tags then too. But look into the forge and fabric repository for that version. Forge biome tags are under forge namespace. Fabric’s c biome tags were named differently back then as well.