rigging a folding up shuriken style weapon

[njrk97]

I have quickly grey-boxed a Shuriken style weapon and i wanted it to be able to fold up, My original plan was to use a bone for each arm with all of them copying the rotation of a control bone, each arm also having a limit rotation on them so once the control bone reaches a certain point they stop rotating. That way as i rotate the control bone the blades fold up and stop at the right place automatically.

It does not seem to be working very well, the limit rotation seems to cause the arms to jump back to their default positions as soon as a move the control bone past their constraint. On top of that animation with it seems impossible as no matter how many keyframes i put in it always wants to go clockwise instead of counter clockwise.

The image and bone set up for reference

As you can see one has jumped back down even though they should all be pointing up.

Am i doing something inherently wrong? Should i just not bother with a control bone? (I suspect it may have something to do with my bones origins but from what i could tell they are all rotated the same way.)

[DanPro]

It may be better to use action constraints. Here is an example. Just rotate the control bone.

Good luck!

Attachments

ShurikenRig.blend (454 KB)

[njrk97]

Thats rather neat, i never knew about the action constraint.

I’m kinda curious how you would set something like that up. Ie how do you create the Action Con to use in the ‘To Action’ field?

[DanPro]

You just create an action for the armature that has keys on the bones you want to move then add an action constraint on each bone in that action to “play” based on the transforms used in the control you choose. Here is a tutorial on how to create them. https://www.youtube.com/watch?v=4SvPkdig5mw&list=PL3wFcRXImVPOQpi-wi7uriXBkykXVUntv&index=20

That tutorial is by Nathan Vegdahl and is part of the Humane Rigging series that I recommend to anyone wanting to learn about rigging in blender.

Good luck!