random_replace_with_properties_processor

random_replace_with_properties_processor

Randomly swaps one block for another while keeping its blockstate properties, so stairs stay facing the right way and slabs stay top or bottom. Use it for weathering: cracking a fraction of the stone bricks, mossing up a wall, stripping some logs.

Ported from RepurposedStructures (TelepathicGrunt).

Minimal example

Strip one in ten dark oak logs:

{
  "processor_type": "moogs_structures:random_replace_with_properties_processor",
  "input_block": "minecraft:dark_oak_wood",
  "output_block": "minecraft:stripped_dark_oak_wood",
  "probability": 0.1
}

Fields

Field	Type	Required	Default	Notes
input_block	block id	yes		Matched by block, so every variant and orientation of it is a candidate.
output_block	block id	no		A single replacement.
output_blocks	array of block ids	no	[]	A set to pick from evenly.
probability	float	yes		0.0 to 1.0. Chance each matching block is replaced.

Give either output_block or output_blocks. One processor entry handles one input block, so weathering several materials means several entries.

Gotchas

• output_block wins if you set both. output_blocks is then ignored with no warning. Setting neither logs a warning per block and changes nothing.
• Reordering the processor list re-rolls everything. The randomness depends on the processor's position in the list, so inserting an unrelated processor above this one changes which blocks get replaced. If you are happy with how a structure looks, do not shuffle the list.
• The pattern is tied to world coordinates, not to the structure. The same piece at the same coordinates always weathers identically, and it does not vary between worlds. Two placements at different coordinates look different.
• Properties the output does not share are dropped silently. Replacing a stair with a full block loses its facing, and a waterlogged input becomes dry if the output cannot be waterlogged.

See also

• Structure Processors overview.
• Vanilla minecraft:rule processors, if you need to match on blockstate rather than block.