Difficulty exporting Blender actions

Not entirely sure I’m doing this right, but thought I’d share my struggles in case there’s a bug or I’m misunderstanding Blender actions.

I’m trying to export a simple test scene with two Actions in Blender, and my goal is that each Action would become a distinct gltf.animations entry, so that they can be played back independently. Here’s my test .blend, and the .gltf output:

actions_test_gltf.zip

The Blender file has two actions, each operating on a different object. A third object in the scene is not animated. The output glTF has 6 animations, with three entries named for each of the two actions. Each animation entry targets only one object. This seems wrong in two ways: (1) the third object shouldn’t be targeted by any animation, and (2) if an action did target multiple objects (although these do not) the channels should all be combined into a single glTF animation entry.

When attempting to load the glTF in three.js I get an error about invalid typed array length. No output or visible error from BabylonJS.

Thanks!

[Kupoman]

When exporting actions, blendergltf does not use the active action on an object. Instead all action and object pairs are checked for compatibility and exported. This would allow one armature to have multiple actions (e.g. walk, run, jump, etc.). This approach is not ideal, and we are working on ways to provide users better options when exporting animations.

That being said, the glTF output of this file is not even passing the validator, so there are also some bugs here. Thanks for the .blend file, I will start looking into fixing up some of the bugs it seems to be hitting. I suspect the bugs are related to animating Blender objects instead of bones, which is not well tested.

[donmccurdy]

Many thanks! It’s working for me now. 😀