Issues with scaling animations & shape-key drivers


(Mica Chan) #1

1) Bone Scaling is causing issues:

Figured out how to upload multiple animations within one model through the Sketchfab Plugin but realized bones with scaling will persist on animation clips that have no scaling differences in their keyframes. I held this problem on Blender early on but keyframing all transformations at the beginning and end of each of my Actions fixed it there, though not here. I tried baking my actions but made no difference. Feels like the scaling keyframes of bones are being ignored here for animation clips that hold the same scaling throughout the animation.

2) Drivers for shape keys aren't Working:

I have a low poly vampire character whose facial expressions I'd like to animate. Knew I couldn't animate the UV coordinates so as a work-around I duplicated the polygon faces that hold the eyes and mouth texture & created a new UV map & texture for them. Using shape-keys I can scale up these faces just above the surface of the default head to change the expression or scale down inside the head to hide them. This works here but it'll only allow me to create one shape-key animation that will be shown on all Actions/animation-clips instead of individual ones per action. I thought the solution was to create Drivers for the shape-keys & link them to custom bone properties which works on Blender but am likely exporting them wrong as Sketchfab doesn't recognize them when uploaded via the plugin.

This user managed to use drivers making me believe it's possible but their post doesn't help me understand how, other than perhaps needing to export to FBX which I have yet do so successfully.

Cube model to troubleshoot scaling and drivers
CubeExample.blend (157.4 KB)

(Moroplogo) #2

There is the same problem with the scaling keyframes of object
( a cube in this example ) .
cube test.blend (576.1 KB)

(Mica Chan) #3

Do also see the same scaling problem like you mentioned. Works properly on blender but not on here like mine. Now I know it's not just bone based.

This also confirms Shape-Keys can be imported correctly when done on the mesh rather than through Drivers but I would still like an alternative to change the expressions based on the action rather than one shape key animation for all Actions.

Thank you for testing this Moroplogo.

(Waleguene) #4


Thanks a lot for reporting and for providing useful samples to debug and test.
These are actually issues on our end, I opened bug tickets, they will be fixed soon :slight_smile:

We will keep you in touch!

(Mica Chan) #5

Hello Waleguene,

You're welcome and thank you for your work and letting me know. The scaling issue would appear to be on the server side but perhaps the driver & shape-key problem is a misunderstanding on my part. From the tests I did today it appears like shape key (mesh) and armature (bone) animations are each considered an object of their own rather than a "character" being one object. This could explain why removing the drivers and keyframing the shape-keys directly resulted in only one animation being displayed called "Scene". Like the help file reads:

If your scene has several animated objects: you get one single animation, where all objects are animated by their current active action.

If I'm mistaken by this do correct me please, as I would love to add blinking animation to my models. A simple and effective way to liven up a model.

(Stephomi) #6

I don't know about blender, but there is definitely an issue when switching between animation in sketchfab.
We fail at resetting some channels, It should be fixed soon.

(Mica Chan) #7

Noticed the scaling issue has been fixed. Thank you Waleguene, Stephomi & other staff members for the support.

While I couldn't figure out how to use shape-keys to change my character's expression and have her blink, I realized I could use bones instead to do the same. Appears to works properly so far.

While my issues are solved I can't locate the button or way to choose an answer & close this topic. May someone guided me please?