Models

Animation

If a model's .bbmodel has animations in it, the model moves. There is nothing to declare and nothing to export.

content/mypack/
  items/furniture.yml
  assets/models/windmill.bbmodel   ← bones and keyframes, as Blockbench saved it

How it works, briefly#

The client cannot animate a block model. A server can move display entities — so an animated model is placed as one display per moving bone, plus one for everything that stays still, and the server retimes their transforms a few times a second.

Two things follow from that:

• It costs entities. A ten-bone model is eleven entities standing in the world. An animated model is a centrepiece, not something to place a hundred of.
• A rig is a tree. A part composes its bone's whole ancestor chain, so rotating a torso carries the arms inside it.

When it plays#

A looping animation loops on its own. A one-shot plays when the piece is right-clicked. That pair is derived rather than declared, because a .bbmodel has no notion of a trigger and those are the two things an animation is usually for.

Right-clicking a piece that animates plays it rather than sitting on it; shift-right-click still sits, if it has a seat.

Telling it how to play#

Blockbench's own loop / hold / once comes across as authored. hold is the one worth knowing: it stops on the last frame and stays there, which is what a door, a lid and a drawbridge all are — without it they spring shut the moment they finish opening.

Everything else is a decision about your server rather than about the model, so it lives beside the piece:

chair:
  material: PAPER
  model: chair
  place:
    animations:
      spin:
        mode: loop      # loop | hold | once, overriding the .bbmodel
        speed: 0.5      # half the authored speed
        priority: 10    # wins when two animations claim one trigger
        blend: 0.25     # seconds to ease in and out of it
        layer: 0        # 0 plays instead of what is running; 1+ plays OVER it
        weight: 1.0     # how strongly, 0-1
        bones: [torso]  # only these bones, and everything hanging off them

An animation nobody mentions plays exactly as authored.

blend is the difference between a model that snaps between poses and one that moves. A quarter of a second covers most things, and it eases out as well as in — going back to rest is a transition too.

priority matters once a model has more than one animation on the same trigger. Higher wins; equal falls back to the order they are in the file.

speed is here and not in a second Blockbench file because the same walk cycle is a stroll on one server and a sprint on another.

Two at once#

layer is how a model plays more than one animation.

Layer 0 is the base — a walk cycle, an idle — and only one plays at a time. Anything above it composes on top, so a wave on layer 1 plays over whichever gait is running rather than replacing it. One animation per layer, so waving twice replaces the first wave and leaves the walk alone.

    animations:
      walk:  { mode: loop, layer: 0 }
      wave:  { mode: once, layer: 1, bones: [torso], blend: 0.2 }

bones is what makes a layer partial. Naming a bone reaches everything hanging off it, so bones: [torso] moves the arms with it — which is what "upper body only" means in practice.

weight scales how far the layer moves what it touches. Half a wave is a smaller wave.

Nothing needs to know about any of this to use it: /rp and the API play an animation by name, and an animation that names a layer goes on that layer.

Playing one yourself#

/rp models              what is around you

From a plugin, a placement can be told to play by name — see the API. On a model worn by a mob, so can MythicMobs.