I would like to combine Mixamo animations from glTF source into a single animation and export it (glTF) for game engine usage.
I grabbed 3 different animation sequences (robot, robot-talk, robot-dance) and imported it into Blender. Everything seems fine. I found a tutorial that tackles the same task but with FBX source. Unfortunately, when I follow the step my new NLA tracks don't animate.
What is the issue, how can one solve this task? Thank you!
The first thing to notice is the "Walk" model does not have the same bone names as the other two (the bones are named "Armature_X", not "ArmatureRobot_X"), so it will need to be fixed to be compatible with them.
Here's how you can do it (starting from your attached .blend).
First do "Delete Hierarchy" on the "Armature_Main_Dance" and "Armature_Main_Walk" armatures, so you only have one armature+model left.
Now select the armature, open up the Dope Sheet and switch to the Action editor. Pick the "Anim_0_Dance" action. You can scrub the timeline to see it works. Click "Stash" to stash it onto your arma. Do the same thing for the "Anim_0_Walk" action even though it doesn't work (we'll fix it later).
Stashing actions tells the glTF exporter to export them. (The "Anim_0_Talk" is already stashed so you don't need to do it.)
Now switch to the NLA Editor. You should see this:
This will export, but the names suck. Rename the tracks like this so the exporter knows what name to use for each animation:
At this point you can star the tracks to see them play.
We need to fix the walk animation. You could rename the fcurves one-by-one in the Dope Sheet but its easier to use a script:
import bpy
ac = bpy.data.actions["Anim_0_Walk"]
for fc in ac.fcurves:
fc.data_path = fc.data_path.replace("Armature", "ArmatureRobot")
(Put it in the Text Editor and hit run.)
You can now star the Walk track to make sure it works.
You're done! Export. You can reimport or test the file in a viewer like https://sandbox.babylonjs.com/ to check it.
