The Animation Stitcher
Grab the script!
1 file availableThe Pile of Awesome Moves
So you just downloaded a perfect set of animations from Mixamo. A yawn, a sneaky walk, a dramatic run, the whole works. They look fantastic as separate files.
But then the game engine politely asks for them as one single file. Ten separate FBX files, each with one animation, are suddenly a puzzle to solve, not an asset to use.
Enter the Stitcher Script
Just put all your Mixamo FBX files in a folder. The script doesn't care about weird names or complex folder structures. A clean list of files is all it needs.
You write down the sequence. It can be a logical flow like Walk, then Jump, then Death, or something fun and chaotic. The order in your list is the order they'll be stitched together.
Run the script. It fires up Blender, kindly asks each file for its animation data, and carefully copies them all onto a fresh, single master timeline. No drama, just results.
Out comes a single, clean FBX file with every animation beautifully lined up. It's ready for your game engine's animation controller, with minimal cleanup required.
01
The Blender RoadblockIf you're on a Mac, you might hit a tiny bump where Blender gets confused by light and camera data in the files. The fix is wonderfully simple: delete those two sections from your FBX, or just comment out one line in Blender's core scripts. A tiny edit, a giant headache gone.
Contents/Resources/5.1/scripts/addons_core/io_scene_fbx/
# if hasattr(lamp, "cycles"):
# lamp.cycles.cast_shadow = lamp.use_shadow
02
A Modern Dance of DataThe real magic is how the script talks to the new animation system inside Blender 5.1. It neatly asks for a "channelbag" (basically a suitcase for all the movement data) from each file and unpacks it perfectly onto a master timeline, with zero messy hand-editing.
Then I open it up in Modo, because I'm an old man, and double check the work.
03
What You Get BackThe result is not just a file. It's a "perfectly" keyframed, single FBX with all your animations back-to-back. You get an instantly usable asset that slots right into a game engine's animation controller.
It's the kind of workflow that takes a tedious manual task and makes it feel like a little magic trick.
This little process was born from a simple need: stop spending time on file management and start spending it on making things move.
The Happy Ending
After a quick run of the script, your folder of individual Mixamo files transforms. The yawn is now peacefully followed by a sneaky walk, which seamlessly flows into a dramatic run. It's all there in one hero FBX, named and ready for your character. The only thing left to do is clean up a couple of looping poses, which the export settings handle with a neat start-and-end keyframe.
A Stitch in Time Saves Nine An old tailor's proverb that applies perfectly to game animation.
