Blockbench Plugin Rigging

Rigging a Limb

Start a project in the Marionette Rig format. It's exactly like Blockbench's Modded Entity format with a few additions: a role dropdown on groups, and an armature bone in every segment.

Roles

A Marionette rig is just groups with a role, set in the Element panel's Marionette role dropdown.

Role
Limb	one chain of segments. Becomes one Limb.builder(...) call in the exported entity
Segment	one link of a chain. Becomes one part entity and one model part
None	a plain group, nested and exported as usual

Segments inside a limb are a chain in outliner order, top to bottom, regardless of nesting.

Joint vs. export origin

A segment has two distinct points:

• The joint is the group's pivot, and the base of its bone. This is the parent-side end, the −Z end. Posing rotates the group about it.
• The export origin is the bone's center, marked with a blue ring. You can think of this as where the hitbox of the part entity will centered.

Resizing a bone moves the export origin by half the length change, so exported geometry offsets change even though you didn't move any geometry. That's intended — the geometry stays put relative to the visible bone.

Bones

Each segment contains exactly one ArmatureBone, which is a visual indicator and a length handle. bone.length is the single source for segment length; there is no separate field.

The bone is pinned to the joint and can't be meaningfully moved or rotated on its own.

Actions

Under Tools, and in a group's right-click menu.

Add Marionette Limb — creates an empty limb group.

Add Marionette Segment — creates a segment plus its bone. With a segment selected, the new one's joint snaps to that segment's bone tip, so you can build consecutive chains this way.

Fit Bone to Geometry — centers the bone center on the geometry's center.