How to rotate cat bone pivot only?

[Anonymous]

After export my CAT character to unreal engine 4 with shared bone settings, when playing animation my character will get missed up, for bones of target skeleton bone has different pivot rotation than my CAT character, after further inspection, I realized the pivot rotation of nearly every single bone is mismatched.

The problem is, I can't simply rotate the pivot of CAT bone, the bone will rotate with the pivot, I tried affect pivot only, Xform and edit poly with no success. I wish to know if there is a way to change the CAT bone pivot via max script, or is there a alternative method counter this problem, please help me.

[ads_royje · Accepted solution]

Hi @Anonymous,

For CAT, the only bone option you have is located on the CAT Root object, the triangle at the base.

While selected, in Modify panel > CATRig Parameters > Bone Length Axis ; you can define which axis is looking down to the child bone, either X or Z.

It is not possible to customize each bone orientation. As CAT is a closed animation system that relies on the bones orientations.

To get things to match, you would need the Rig from the game character to create animations for it.

You can export the Rig from Unreal as FBX and import in Max :

https://docs.unrealengine.com/latest/INT/Engine/Content/FBX/SkeletalMeshes/#animations

With that rig, you can now create new animations for that character in UE4.

Using the UE4 rig in Max with IK solvers.

If you'd like to use CAT as animation system, still doable but a lot of work.

For animation to export correctly, you need the UE4 rig to keep same hierarchy and orientation.

Using CAT, you can position CAT bones to match the UE4 rig.

Each UE4 bones will have to follow CAT. To do so, you could use the Link Constraint controller on each UE4 bones to have a 'fake' parent in CAT rig.

This would have CAT to drive the UE4 bones, that you can export baked.

This is a long process but would work.

I hope this can help ! 🙂

[Anonymous]

Thank you so much!

I followed your suggestion, imported the UE4 skeleton, use link constraint to drive the UE4 bone, repositioned the UE4 bone and reskinned the mesh, it's a bit tedious, but the result is very rewarding. Now I can use this "binded" CAT rig for other humanoid character as well !

Thanks again!

[ads_royje]

Awesome! 🙂

Happy to read it works well for you !!

Thank you for your feedback! 🙂