I have block model file pearlstone.json :

{
  "parent": "minecraft:block/cube_all",
  "textures": {
    "all": "anomaly:block/pearlstone"
  }
}

And this textures structure:

- textures
   - block
      - pearlstone.png
   - item
      - pearlstone.png
   - effect
      - pearlstone.png
   - special
      - pearlstone.png

I want to use texture path "all": "anomaly:effect/pearlstone" or "all": "anomaly:special/pearlstone" inside pearlstone.json model file, but this block shows as missing texture in game.
If I change texture path to "all": "anomaly:item/pearlstone" this block shows as expected.

• I noticed vanilla has effect folder by default and tried to put textures here but it didn't work.

Same problem occurs with custom models. I can place model file wherever I want and load it using Identifier (for example resources/models/special/laser_beam.json, but it still unable to use textures outside block/item folders)

Is this intended behavior and if so, where do I place textures for custom models that aren't associated with blocks or items?

Turns out you have to add directories to the atlas for the textures inside to be usable, to do this you can put an atlas definition at assets/minecraft/atlases/blocks.json with the contents

{
  "sources": [
    {
      "type": "directory",
      "source": "effect",
      "prefix": "effect/"
    }
  ]
}

by default, vanilla only adds the block, item, and entity/conduit directories to the blocks atlas (as well as some individual files).

Wiki page on Atlases: https://minecraft.wiki/w/Atlas

Credit ioblackshaw on Fabric Discord.