LoopKit (Blender Add-on)

LoopKit is a Blender add-on by Vanilla Loop that turns Blender into a fast preview and editing station for Unreal Engine mannequin animations. Browse a folder of FBX animations, apply them to Manny or Quinn with one click, edit them on a full Rigify control rig and bake the result back to a clean, export-ready UE skeleton.

• Blender 4.2 or newer (Windows, macOS, Linux).
• The bundled Rigify add-on (ships with Blender, LoopKit enables it automatically when needed).
• FBX animations exported for the UE mannequin skeleton family (UE5 Manny / Quinn; the UE4 mannequin is supported as well).

1. Download the add-on from vanillaloop.com/loopkit-download.
2. Open Blender and go to Edit > Preferences > Add-ons.
3. Click the arrow in the top-right corner and choose Install from Disk...
4. Select loopkit-x.x.x.zip (do not unpack it) and enable LoopKit.
5. The LoopKit tab appears in the 3D Viewport sidebar. Press N if the sidebar is hidden.

The LoopKit panel has four sections, top to bottom:

• Characters: add bundled models, import your own, choose the target.
• Animations: browse a folder of FBX clips and apply them.
• Options: behavior switches for applying animations.
• Animation Editing (Rigify): create an editing rig, bake or discard.

A status line at the bottom always shows the result of the last action.

Adding a bundled model

Click one of the Add: buttons (e.g. Add: SKM_Manny). The model is imported with known-good settings and automatically becomes the target, the character that receives animations. Each new character is placed next to the previous one so models never overlap.

Importing your own character

Click Import Custom Character... and pick any FBX whose skeleton uses the mannequin bone hierarchy (pelvis, spine_01..., thigh_l, and so on). Always import characters through LoopKit: it forces the correct FBX settings (no Automatic Bone Orientation, default scale), which guarantees animations will match.

The character list

Every mannequin-compatible armature in the scene is listed. Click a name to make it the target. The highlighted entry is the current target.

• A red entry marked [EDIT] means that character has an active editing rig. Clicking it jumps straight to its rig in Pose Mode.

Changing the bundled-models folder

Edit > Preferences > Add-ons > LoopKit > Models Folder. Any FBX files in that folder appear as one-click Add: buttons.

1. In the Animations section pick the folder that contains your FBX animation files. The list fills in automatically; the refresh icon rescans the folder.
2. Click a clip in the list and it is applied to the target character immediately (see Auto-Apply on Select in Options). You can also use the big Apply Animation button.
3. Use the small arrow at the bottom of the list to filter clips by name, handy for large packs.

Every applied clip is stored as a Blender action (protected with a fake user), so you can also switch between previously applied clips in the Action Editor / Dope Sheet.

Automatic pose correction

LoopKit compares the rest pose of the animation's skeleton with your character:

• Poses match: the action is assigned directly (instant).
• Poses differ (animation packs with a different hand or arm bind pose, different scale, a character imported with Automatic Bone Orientation): LoopKit automatically performs a frame-by-frame retarget with rest-pose correction. The first apply takes a few seconds; the result is cached, so every next apply of the same clip is instant.

The animation always ends up looking exactly like the author intended: no A-pose offset, no scale explosion.

• Skeleton: manual target picker (normally use the character list).
• Auto-Apply on Select: clicking a list entry applies it instantly.
• Set Frame Range: scene frame range follows the animation length.
• Do Not Re-Import: unchanged files are reused from cache.
• Search Subfolders: scan the animation folder recursively.
• No Pose Correction (1:1): skip the retarget, diagnostics only.

Creating the rig

With an animation applied, click Create Rigify Rig (Edit). LoopKit:

1. builds a Rigify metarig matched to your character's joints,
2. generates the full control rig,
3. transfers the current animation onto the controls (torso, spine, neck, head, shoulders, limb FK and IK targets with foot roll),
4. binds the UE skeleton to the rig and hides it.

The panel shows a red EDIT MODE ACTIVE banner while a rig exists.

Editing

• Work in Pose Mode on the rig (LoopKit puts you there automatically).
• Click a control's wire shape to select it; G move, R rotate.
• IK/FK sliders and snap buttons live in the N > Item panel (Rig Main Properties) while the rig is selected.
• Limbs start in FK, a faithful 1:1 reproduction of the animation. Use the IK snap button on a limb when you want planted feet or hands, then edit the IK target.

Finishing

• Bake to Skeleton: writes the edited animation back onto the clean UE skeleton and removes the rig, metarig and widgets. The character is ready to export.
• Discard Changes: removes the rig. The original action was never modified, so nothing is lost.

Editing several characters at once

Each character can have its own rig at the same time. The character list marks every character in edit mode in red with [EDIT]; click one to jump to its rig. Bake/Discard always applies to the character shown in the red banner.

Good to know

• Fingers, twist bones, UE IK bones and neck_02 are not bound to the rig, so they keep the original animation exactly (zero drift when baking).
• While a character is in edit mode, applying new animations to it is blocked: Bake or Discard first. Other characters can still receive animations.

After baking, export the character with File > Export > FBX using your usual UE animation export settings (limit to the armature, bake animation). The skeleton is clean: plain bones with keyframes, no constraints, no helper objects.

The animation looks wrong / the character is deformed.
Make sure the character was imported through LoopKit (Add buttons or Import Custom Character). Characters imported manually with Automatic Bone Orientation or with applied scale are auto-corrected by the retargeter, but the cleanest results come from LoopKit imports.

The Apply button is greyed out.
No target character. Add or click one in the Characters list.

Create Rigify Rig is greyed out.
The target has no animation yet. Apply a clip first.

I applied a clip but want the untouched original back.
Disable Do Not Re-Import and apply again (or re-export the FBX). LoopKit imports a fresh copy.

Skeleton excluded from view error while baking.
The character's collection is disabled in the View Layer. Re-enable it and bake again.

Product page and animation packs: vanillaloop.com. Questions and bug reports are welcome on our Discord.

LoopKit is built by Vanilla Loop. Mannequin models (SKM_Manny / SKM_Quinn) are © Epic Games, Inc., provided under the Unreal Engine EULA. The editing rig is powered by Blender's bundled Rigify add-on.