Block Texture Variation

Texture variation is strictly a client-side rendering feature controlled inside RP/textures/terrain_texture.json. Instead of pointing a texture shortname to a single file path string, you pass an array of objects under the variations key. When the world renderer builds a chunk mesh, it hashes the X, Y, and Z coordinates of each block position and uses that hash to pick one entry from the variations list.

Because the selection is driven by a deterministic coordinate hash rather than a pure random number generator, the chosen texture stays the same every time the chunk loads. All players looking at the same coordinates will see the exact same variant, and breaking and replacing the block at that exact spot will yield the same appearance.

Open or create RP/textures/terrain_texture.json. Under the texture_data object, define the shortname your custom block will reference. Inside that shortname's object, replace the usual string path with a variations array inside the textures property.

Each item in the variations array is an object containing a path string and an optional weight number. The paths omit the file extension and resolve from the root of the resource pack, just like standard texture definitions.

{
  "resource_pack_name": "my_custom_pack",
  "texture_name": "atlas.terrain",
  "padding": 8,
  "num_mip_levels": 4,
  "texture_data": {
    "wiki:cobbled_shale": {
      "textures": {
        "variations": [
          {
            "path": "textures/blocks/cobbled_shale_0",
            "weight": 60
          },
          {
            "path": "textures/blocks/cobbled_shale_1",
            "weight": 25
          },
          {
            "path": "textures/blocks/cobbled_shale_2",
            "weight": 10
          },
          {
            "path": "textures/blocks/cobbled_shale_fossil",
            "weight": 5
          }
        ]
      }
    }
  }
}

The weight property controls how often a given texture appears relative to the other entries in the same variations list. Weights do not need to add up to 100, though making them sum to 100 makes it easy to read them as percentages. The game totals all weights in the array and gives each entry a slice of the probability pool equal to its weight divided by the total.

If you leave weight off every entry, all variants show up with equal frequency. This is usually what you want for natural noise textures like sand, gravel, or grass tops. Weighted entries are much better for man-made blocks or stone: you can give one clean base texture a weight of 80, two slightly cracked variants a weight of 9 each, and a rare mossy or fossilized variant a weight of 2.

Once the shortname is configured in terrain_texture.json, the behavior pack block definition does not need to know that variations exist. You assign the shortname (in this example, wiki:cobbled_shale) to your block the exact same way you assign a single texture.

In modern custom blocks that use minecraft:geometry and minecraft:material_instances, pass the shortname into the texture field of your material instance. If your block uses per-face material instances (such as a pillar with different top and side textures), each shortname can independently use its own variations array in terrain_texture.json.

{
  "format_version": "1.20.80",
  "minecraft:block": {
    "description": {
      "identifier": "wiki:cobbled_shale"
    },
    "components": {
      "minecraft:destructible_by_mining": {
        "seconds_to_destroy": 1.5
      },
      "minecraft:geometry": "minecraft:geometry.full_block",
      "minecraft:material_instances": {
        "*": {
          "texture": "wiki:cobbled_shale",
          "render_method": "opaque"
        }
      }
    }
  }
}

If you alternatively assign textures to your block using the legacy RP/blocks.json file instead of minecraft:material_instances, the setup works identically: point the textures property in RP/blocks.json to your wiki:cobbled_shale shortname, and the variations defined in terrain_texture.json will render in the world.

Keep in mind that coordinate-based variation only applies to blocks placed in the world. When the block is held in a player's hand, dropped as a floating item, or shown in an inventory slot, there are no world coordinates to hash. In those contexts, Bedrock always renders the first entry (index 0) in your variations array. Always put your cleanest, most representative base texture first in the list so the inventory icon looks right.

Applies to all modern Bedrock versions (1.16.100+ for material_instances, and earlier versions via RP/blocks.json). No experimental toggles are required.

Read out of the game itself, so the ids match the version you are building for.