RIG PROOF · BLENDER → UNITY → UNREAL

Prove your character arrives exactly as it left Blender

It looks right in Blender. Then it lands in the engine in a T-pose, at 1/100 size, or with half its clips missing. Rig Proof catches those mistakes before you export, and proves the import matches: every bone, every frame, every clip.

Download the free Blender add-on Unity + Unreal verifiers on Fab →

Free add-on: Blender 4.2 LTS to 5.2 LTS, GPL. Verifiers: one purchase on Fab includes both Unity and Unreal.

The Rig Proof sample kit rendered in Blender: the Sentinel biped and a tiger in white, pink and cyan, and blue skins

How it works

Three steps, the same on every character: a biped, a quadruped, anything with a skeleton.

  1. Check in Blender. The free add-on runs 74 pre-flight checks and explains each problem in plain words: the armature left in Rest Position, an unapplied scale, NLA tracks baked into clips, textures that will not travel. Ten of them fix with one click, and each fix is followed by proof that the animation did not move.
  2. Write the ground truth. One file records every deform bone on every frame of every clip, in metres, independent of any engine's axis convention.
  3. Verify in the engine. In Unity or Unreal, Rig Proof compares the imported character against that file and answers RESULT OK — N bone-frames verified, or a FAIL that names the clip, the bone, the frame and the likely cause.
What Rig Proof checks: 74 pre-flight checks in Blender, a ground-truth file, and a bone-by-bone comparison in Unity and Unreal
The Unity report: PASS for the correct export, FAIL with the reason for the same character exported with Rest Position left on
Real reports from the shipped sample kit: the correct export passes, and the same character exported with Rest Position left on fails with the reason and the fix.

Get it

Rig Proof for Blender

Free · GPL-2.0-or-later

The pre-flight checks, the one-click fixes and the ground-truth writer.

  • Blender 4.2 LTS, 4.4, 4.5 LTS, 5.1, 5.2 LTS
  • Edit ▸ Preferences ▸ Add-ons ▸ Install from Disk… ▸ the zip
  • Panel: 3D Viewport ▸ N ▸ Rig Proof
Download the add-on

Rig Proof for Unity and Unreal

On Fab · one purchase, both engines

The verifiers that compare your import against the ground truth, plus a textured sample kit with a correct and a deliberately broken export of each character.

  • Unity 2022.3 LTS, 6000.0, 6000.3, 6000.5, 6000.6
  • Unreal Engine 5.4, 5.5, 5.6, 5.7, 5.8
  • Headless and command-line modes for CI
See it on Fab →
Supported versions: Blender 4.2 LTS to 5.2 LTS, Unity 2022.3 LTS to 6000.6, Unreal Engine 5.4 to 5.8

Updates

The Blender add-on
The download button on this page always gives the newest version. To update, install the new zip over the old one, then restart Blender: Blender keeps the old code loaded until it restarts.
The Unity and Unreal verifiers
Updates arrive through your Fab library: open Fab, or the Fab plugin in your engine, and download the newest version. When Unity, Unreal or Blender ships a new version, Rig Proof is tested on it again before the supported list changes.
What changed
Each add-on release lists its changes on the releases page.

Support

Questions, a character that fails when you think it should pass, or a version you need:

marcel.gilbert.dev@gmail.com — answered within two business days. Include the report file Rig Proof writes; it names the versions and the settings used.

What Rig Proof does not compare (for example a turn already present on the first frame, or the shape of a morph target) is listed plainly in the documentation that comes with it.