Rigs & Multi-Rig¶

A scene rarely holds one thing. Two characters, a prop, and a camera all live in the same Harmony node graph or Maya outliner — and if you export them as one undifferentiated pile, they arrive on the other side as one undifferentiated pile.

The Rig column is how you keep them apart. It's a tag written into the file, and on import it decides what gets built as a separate unit:

Application	One rig becomes
Blender	One armature
Maya	One group, with that rig's roots under it
Harmony	One node group

The Rig column¶

Root rows get an editable dropdown. Child rows get dimmed text and a tooltip saying whose rig they inherit — a child is never a separate choice.

The column appears on all four pages, and the grouping is shared between the two formats. One scene, one grouping, whichever file it leaves as: change a rig name on the .anm export page and the .pvt export page reflects it immediately.

Three things you can do in the cell¶

Double-click the Rig cell to type in it. The cell is an editable combo: double-click puts a cursor in the text, or use the chevron to pick from the list of rigs already in the scene.

Action	Result
Pick an existing rig from the dropdown	Merges this chain into that rig
Double-click and type a name	Renames the rig — every chain carrying that tag follows
Choose `+ New rig…`	Prompts for a name and moves only this chain into a new rig
Clear the cell	Restores the automatic grouping for this chain

The difference between typing a name and choosing + New rig… is worth internalising: typing is a rename that affects everyone sharing the tag; + New rig… splits this one chain off and leaves the others alone.

So if you have spaceship and turbine both tagged spaceship and you double-click either cell and type freighter, both follow — you renamed the rig, you didn't move one chain out of it. To move just one, use + New rig….

The connectivity lock¶

There is one rule OTS will not let you break:

A connected chain can never be split

A child always shares its parent's rig. You can merge two disconnected roots into one rig; you can never put a bone in a different armature from the bone it hangs off.

This isn't a UI limitation — it's what makes the import meaningful. A bone in a different armature from its parent has no parent, and the pose would be wrong.

You want to	Allowed?
Merge two separate character roots into one rig	✅ Yes
Put a prop's root in its own rig	✅ Yes
Move a camera chain into a character's rig	✅ Yes — it's a separate chain
Split a spine into two rigs at the waist	❌ No — they're connected

So the atomic unit is the chain, and the thing you're deciding is which chains share a rig.

How OTS proposes a grouping¶

You rarely have to do anything: OTS fills the column in for you and is usually right. It picks each root's rig by walking down this list until something answers:

Your own override — anything you typed or picked stays put.
A dedicated camera chain → Camera (or Camera_1, Camera_2, … if there are several).
The application's own hint — in Maya, the group the joint sits under.
The enclosing group — in Harmony, the group in the node path.
The root's own name, with peg suffixes stripped.
Rig, as a last resort.

Camera numbering is stable

When there's more than one dedicated camera chain, the roots are sorted by name before being numbered. So Camera_1 and Camera_2 mean the same thing every time you export — they don't shuffle because you happened to select things in a different order.

A camera that lives inside a character chain — a peg parented under the rig, driving a camera — is not a dedicated camera chain. It inherits the character's rig, which is right: it moves with them.

In practice¶

Two characters in one file¶

Scan both. OTS will usually name each rig after its root, and you'll see two rig names in the column already. If it guessed one name you don't like, type over it.

On import, Blender creates two armatures, Maya creates two groups, Harmony creates two node groups.

A character and its camera¶

The default. Your character chain gets its name, the camera chain gets Camera. On import, Create Rig builds the character and Create Cameras builds the camera — separate buttons, because they're separate things.

Deliberately merging¶

Two props that you want treated as one rig on the other side: pick the first prop's rig name from the second prop's dropdown. They merge. They're disconnected roots, so this is allowed.

Why Blender has no Rig column¶

Two of the three applications give you the column; Blender doesn't. That isn't an inconsistency — it follows from what a "rig" actually is in each one.

	What a rig is	Can a bone move to another rig?
Blender	An armature — a real object with its own datablock. A bone cannot exist outside exactly one armature	No. Blender's own data model forbids it
Maya	A convention. A joint is just a transform node in the DAG; there is no armature object. A "rig" is usually the group you parented the root under — or nothing at all	Yes — it's only a reparent
Harmony	A convention. A peg is a node in the graph; a "rig" is the enclosing group	Yes

So in Blender the question is already answered before OTS is involved, and the column is locked: each selected armature exports as its own rig, named after itself. Letting you retag a bone into another rig would mean promising something the export can't honour — a bone whose parent lives in a different armature has no parent.

In Maya and Harmony the grouping is genuinely a convention, so it's genuinely a decision, and the column is where you make it. OTS proposes a sensible default — in Maya, the joint's nearest non-joint ancestor; in Harmony, the enclosing group — and lets you correct it.

The connectivity lock covers all three

Maya and Harmony being editable doesn't make them loose. The lock still applies everywhere: you can merge disconnected roots; you can never split a connected chain. So the freedom in Maya and Harmony is only ever "which chains group together" — never "break this chain in half". Blender gets the same guarantee for free, from its data model.

On import, all three honour rig tags fully: a file with three rigs produces three armatures in Blender, three groups in Maya, three node groups in Harmony.

See In Blender and In Maya.

Names across applications¶

Rig names travel as plain text and are used to name the armature or group that gets built. Keep them simple — no slashes, no leading or trailing spaces — and they'll survive all three applications intact.

If two chains in different rigs contain items with the same name, that's fine: OTS matches on full paths, not bare names, so same-named bones in two rigs stay distinct.