Bone animation broken

Help & Support
1

Hi Everybody!
So I got an issue and I’m not sure where it’s coming from. Here’s the scene:
https://playcanvas.com/editor/scene/593241
(not sure if I did that right. Let me know if there’s another link/method I should use. I’m new to these boards.)

I have a very long joint chain (314 bones) and when I bring the animation into Playcanvas it breaks. Really badly. Here’s a shot of how it looks in Maya:

aminoAcid_inMaya
aminoAcid_inMaya956×655 125 KB

Here is what it looks like in Playcanvas:

aminoAcid_inPC
aminoAcid_inPC755×554 36.1 KB

As you can imagine, when it animates it gets all sorts of crazy.

It looks like the issue starts at bone # 257. Is there a limit to the number of joints Playcanvas supports? Like more than 256 bones is not supported or something? If so, is that a limit on joints per joint chain/skeleton, per object, or per scene?

If not, any idea of the issue here?

Any suggested solutions/workarounds would be appreciated.
Thanks!

2 Likes
2

Anyone experiencing this issue or even trying to use these kinds of bone animations?

3

over 256 bones would kill most engines, not sure what the limit of Play Canvas is but Unity and Unreal top out around 60 to 128 typically in a model, and a vertex can only be influenced by 4 bones tops in most engines, some 8

You might need to break the model and bones into smaller and more numerous chunks.

1 Like
4

Thanks for the reply, Mike!

So the limit is based on the object/model not the entire scene or imported FBX? (This is really my main question)

So in other words, if I split up the joint chain in Maya and use constraints to connect the chains that should work?

(NOTE: This scene actually worked within Unity, but I think Unity split up the joint chains under the hood?)

Thanks!
PJ

5

Unity splits it up for sure under the hood. Look in the hierarchy window in Unity and you’ll see it split into 64,000 polygon chunks for the mesh itself.

I don’t rig in Maya unfortunately so I couldn’t tell you if the constraints will export into Play Canas,

6

Yeah.
Constraints don’t transfer so I would bake the animation in to the joints.

I’m just trying to figure out if I need to split the actual mesh up somehow or if I can get away with just splitting up the joint chain.

I’m working on another issue right now, but I will test this out a bit later…

7

I typically bake for Web GL

8

Yep, there’s a 256 bone limit in PlayCanvas. The indices that are used to select bones are 8-bit.