FBX animation combiner workflow

This workflow combines a folder of compatible FBX character files into one Blender file with one armature, one skinned mesh, and many reusable Actions. It is useful when every FBX contains the same character rig and mesh, but each file has a different animation clip.

The result is an animation library file instead of many separate FBX files.

Files

• Add-on: fbx_animation_combiner_addon.py
• Panel location: 3D View > Sidebar > Animation > FBX Combiner

Assumptions

• All FBX files target the same armature structure.
• All FBX files use the same bone names.
• All FBX files were exported from, or generated for, the same skinned character.
• Each FBX usually contains one animation clip.
• The character rest pose should match across files. For Mixamo-style animations, this normally means T-pose.

Empty-project workflow

1. Open a new empty Blender project.
2. Enable the FBX Animation Combiner add-on.
3. Open 3D View > Sidebar > Animation > FBX Combiner.
4. Set FBX Folder to the directory containing the FBX files.
5. Run Combine FBX Animations.

The first imported FBX becomes the master character. Its armature and mesh stay in the scene. Each later FBX is imported temporarily, its animation is copied into a clean Action on the master armature, and then its temporary objects are deleted.

Settings

• FBX Folder: the directory containing the compatible FBX files.
• Overwrite Existing Actions: enabled when re-importing the same folder and replacing old Actions.
• Log To File: writes a detailed combine log.

Everything else is intentionally automatic: Actions are named from filenames, fake users are enabled, later imported FBXs are deleted after their Actions are copied, and the transfer path is direct-copy because the files are assumed to target the same rig.

What the add-on creates

After a successful combine, the Blender file should contain one master armature and mesh, plus Actions named from the FBX filenames:

idle
walk
run
jump
reload
death

These Actions can then be selected in the Action Editor, pushed to NLA, cleaned with the Root Motion Cleaner, or exported through glTF/FBX.

Root motion cleanup

Some FBX imports store forward movement on the armature object location curves instead of only on a root bone. If the combined animations should be stationary/in-place, run the Root Motion Cleaner add-on afterward.

Mixamo note

This add-on still works for Mixamo animation folders. For Mixamo-style downloads, the source and target character should be in T-pose. If the character is in A-pose, convert it first: Convert an A-pose character to T-pose.

Limitations

• The add-on expects compatible skeletons. It is not a full retargeting system for unrelated rigs.
• It expects one main animation Action per imported FBX.
• If one FBX contains multiple animation takes, those may need separate support.
• If arm rest poses differ, especially A-pose versus T-pose, arms may not line up even when bone names match.