Messed up animation when importing 3D scene DAE

[dodgyville]

Operating system or device, Godot version, GPU Model and driver (if graphics related):
godot 3 (tip), ubuntu

Issue description:
When importing a DAE that contains a rigged mesh and animation exported from blender using the better collada exporter, the resulting animation flips around and generally misbehaves.

Here's an example video, blender is running on the right (slowly) and the equivalent import for godot is on the left.
https://www.youtube.com/watch?v=fBVpZ2v6Nt4

EDIT: updated link

[Zireael07]

The link is bad (are you sure it should have "edit"? it leads to creating a new video i.e. prompting to create a channel)

[dodgyville]

Oops, thanks, corrected!

[rminderhoud]

FWIW I am also having a similar issue with rigged meshes and animations except I am not importing a COLLADA file. It would be good to identify whether this is an issue with the COLLADA importer or with the animation system.

[karroffel]

I experience the same thing, but it looks like it's Better Collada's fault.

Comparison Blender - Godot: https://gfycat.com/ScentedConfusedBeardedcollie

Watch the head movement. It's not completely smooth in Blender either but it's much more bumpy in Godot.

I also tried the two glTF exporters for Blender. One exports the meshes incorrectly but has proper animations, the other one has (almost) proper meshes but no animations.

Here you can see that the head movement is a lot smoother like in Blender: https://gfycat.com/FarawayHideousChimpanzee

So the problem seems to actually be in the Better Collada exporter and not Godot.

[rminderhoud]

@karroffel - Do you have a 3rd software you can use to test the penguin that was exported with Better Collada exporter? What about when you re-import the Collada file back into blender?

EDIT: I did my own tests and I can't reproduce it with a random Collada file I found online. The steps I performed:

1. Load the Collada file directly into blender -- Works
2. Load the Collada file directly into godot -- Works
3. Load the Collada file directly into blender and export using better exporter -- Works

wolf.zip

[dodgyville]

I found this nugget while looking at an unrelated 3D program that exports to DAE. This describes the symptoms of my problem but I'm not sure how it applies to exporting.

"COLLADA does not support a native 4x4 matrix transformation format, so we write to the file as a translation or rotation. If you use this to make smoothed animations, this can lead to gimbal lock issues, which appear as sudden 180 flips in playback. You many need to manually edit rotations or smoothing settings."

[rminderhoud]

@dodgyville Interesting find but it looks like the collada export uses a 4x4 matrices?

Writing the bone matrix to collada:
https://github.com/godotengine/collada-exporter/blob/master/io_scene_dae/export_dae.py#L1113

Here is how it makes the 4x4 matrix string:
https://github.com/godotengine/collada-exporter/blob/master/io_scene_dae/export_dae.py#L61

[rminderhoud]

@dodgyville are you able to share the file you've been working with?

[dodgyville]

It's a pretty large file (256mb - several minutes of animation), I'll see if I can shrink it.

I've just noticed that if I bake the animation using the Pose data then the import to godot plays smoothly but the character does not move around.

[rminderhoud]

So you are now able to import the skeleton (armature) into godot correctly with animations but the mesh does not move? Was the issue always only with the mesh or was the armature previously "spinning" also?

[dodgyville]

The bone animation deforms the mesh correctly and there is no flipping but the character does not move around the scene and is instead pinned in place. So close! Video

[dodgyville]

OK, update on this. In Blender, changing the rotation type for objects (3D View > Properties region (N) > Transform panel > Rotation) from XYZ Euler to Quaternion (WXYZ) helps a lot when exporting as DAE. There's now an issue with the object drifting around but it's closer than ever.