Mobs only spawn from spawners - not from low light levels - 1.20.1

[astral geyser]

Hey is there a way to create a new dimension such that:

1. There is ambient light so players can always see
2. Mobs still spawn, but when there are spawners present, never generally, due to light levels

Thanks!

[restive lotus]

I'm a little confused, your title seems to contradict your stated goals

[astral geyser]

Let me be clear:

1. I want my dimension to have ambient light so the player can always see.
2. I want my dimension to spawn mobs via mob spawners - that is, the ambient light should not prevent mobs from spawning.
3. I never want mobs to spawn "naturally" - that is, with no spawner around.

If I have to let the ambient light thing go, that's fine.

Thanks!

[earnest elm]

You would have to look up some guides on worldgen. What you are asking for requires a lot files in your datapack and some parts very well might not work due to hardcoded spawn behavior of certain mobs.

If you are asking for anyone here to create this for you... you should probably read the pinned messages and look elsewhere.

[restive lotus]

Well increasing the ambient light is easy, that's done in the dimension_type file. Making it high enough will both allow players to see and hostile mobs to not spawn naturally (if they are the type of hostile mob that needs darkness--there's some that don't).

As for the mob spawners, that's technically possible but may require modifying the NBT of mob spawners in the world to have custom_spawn_rules in their spawn_data so they can spawn at higher light levels. Though it's also possible that won't be necessary, you'll have to test it

[earnest elm]

Above assumes neutral mobs are allowed to spawn naturally, if you don't want that, each biome file requires editing to remove the spawns that are not bound by light levels.

[astral geyser]

I am a modder, this behavior is going in a Java mod so I do have some finer level of control here.

I just dont really understand the nature of the 3 variables in my dinension_type file

"Ambient_light",
"Monster_block_spawn_limit",
"Monster_spawn_rules" (or something, not at my computer)

And how they interact with each other, thought this may be an easy thing if I just understand the variables.

[restive lotus]

OK, well this is a data pack server

I can't help you make a mod

[astral geyser]

Sure but

It's the same dimension_type file

Right?

[restive lotus]

Yes, but you said you will have more granular control

Which is meaningless to me

[astral geyser]

Oh, sure sure - yeah, if I had too, but this seems like something they give you the variables to do in JSON, I could mod if I really had too,

[restive lotus]

• Ambient Light is the visual light that players can see at
• Monster spawn block light limit is the maximum inclusive light level that hostile mobs need to spawn in under normal circumstances, which defaults to 0, total darkness, since the caves and cliffs update
• Monster spawn light level is the light level range that hostile mobs can spawn at under special circumstances, namely thunderstorms

[astral geyser]

If zi can do this via biomes this is great, only have one biome in the dim 👍

[astral geyser]

Very helpful, appreciate that thanks!