---
title: "rig asset type"
description: "A skeleton, as a composite asset. A rig is its own primitive — not a mesh and not an animation. The folder <name>.rig/ carries:"
section: "Types"
slug: "types-rig"
canonical: "https://origozero.ai/docs/types-rig"
updated: "2026-08-22T07:41:56.202259384+00:00"
tags: ["asset-type", "reference"]
---

# rig asset type

- **`rig.json`** — the readable skeleton document, the asset's *primary*.
  Consumers reference the `.rig` asset's guid, never this inner file. It holds:
  - **`bones`** — ordered bones, each with a `name`, a `parent` index (-1 for a
    root), the `node` index it maps to, its `rest` local transform
    (translation / rotation / scale relative to the parent — the bone's offset and
    length), and its `inverseBind` matrix (16 floats). The `rest` is the
    hand-editable driver for posing and shape-preserving retargeting; the
    `inverseBind` is what skinning reads.
  - **`profile`** — the retarget holder: `base` plus a `roles` map from each
    canonical humanoid role to the bone name that fills it. Present when the
    skeleton is a humanoid; this is the map that drives retargeting and the thing
    you edit to fix a mis-mapped bone.
  - **`humanoid`** — the structural classification (`isHumanoid`, `hasHips`,
    `hasHead`, `armChains`, `legChains`, `mappedRoles`) that gates whether the rig
    joins the shared humanoid-animation pool.

The format is JSON, not binary, because a rig is small structural metadata an
agent inspects and hand-corrects — the bulk binary `.mesh`/`.animation` carry
their own decode paths, but a rig is meant to be read.

A skinned `.mesh` references a `.rig` (the mesh keeps only per-vertex skin
weights; the skeleton lives here). An `.animation` references its source `.rig`.
Retargeting maps a clip from one rig onto another, routing each bone through its
canonical role in the shared BASE rig (`rigs/base_humanoid.rig`).