Incorrect model transform when running animations


(Peanut64646) #1

Hello,

I uploaded an animated model in .fbx format (this model: https://sketchfab.com/models/5cc485dcc3c7497b84784a1727a1dbdb) and the animations appear to be working on the Sketchfab view, and it also works properly if I re-download and open in .fbx format.

However, when I try to download the same model in GLTF format, the model shrinks, rotates, and moves forward from its original position upon running any animations, and the walk animation is distorted when it runs.

Here’s a short example video showing my model loaded in GLTF format, and then once an animation is run the model’s transform changes


#2

Hmm maybe @waleguene can help.


(Waleguene) #3

Hi @peanut64646,

Thanks for the details and for the video, it helps a lot!
It seems to be caused by the way skinning animation is exported in glTF, and by the huge scale applied to the Game_engine object. I don’t have any clear answer at the moment, we will need to dig into this issue, but it seems that the static pose is scaled with the high value and then, using the skinning is bringind back the model to scale 1.
For the animation distortion, I don’t really see it when importing the glTF in this Three.js viewer which we use as reference. Which renderer/tool are you using in your video ? (The model at the beginning of the video looks like the monkey of jMonkeyEngine)

In the meantime, could you try to test with a new upload after having removed the huge scale to see if it fixes ?

Thanks,


(Peanut64646) #4

Sorry for the late response

I am using JmonkeyEngine

I had some time to upload another animated model in .fbx format and downloaded it in .gltf format, but it is causing the same distortion as in my original video - one single animation is distored (the rat’s walk animation in this case) and all of the animations alter the model’s rotation and scale when an animation is run https://sketchfab.com/models/f9893c3dacdb48a3bcff0106ea5a5404#

The first model of the female character was created using MakeHuman, (so I’m not sure where the unusually large scale may have come from) and I made the second Rat model from scratch in Blender. It doesn’t appear to have a different scale for the Model compared to the Armature (unless I’m confused and this isn’t what you meant by checking the scale of the static pose vs the scale of the model)

I also tried to view my model in the viewer that you linked, although it doesn’t seem to work. It says there are errors at the bottom of the screen when I try to upload my downloaded folder titled “tiffany” containing the textures, .GLTF, and .bin files for my model.