Bone that moves another bone that moves a third bone

Wondering how to accomplish a certain animation task? Ask here.

Moderators: Víctor Paredes, Belgarath, slowtiger

Post Reply
Daxel
Posts: 967
Joined: Wed Mar 27, 2019 8:34 pm

Bone that moves another bone that moves a third bone

Post by Daxel »

Yes, this is what happens when I'm in quarantine. I made a smartbone that moves another smartbone that moves a third bone. When I move the first one, the second one moves, but not the third. Is there a way to make this work, like some script or technique?
User avatar
synthsin75
Posts: 9934
Joined: Mon Jan 14, 2008 11:20 pm
Location: Oklahoma
Contact:

Re: Bone that moves another bone that moves a third bone

Post by synthsin75 »

You can do that with nested bone layers, but probably not in the same bone layer.
User avatar
hayasidist
Posts: 3492
Joined: Wed Feb 16, 2011 8:12 pm
Location: Kent, England

Re: Bone that moves another bone that moves a third bone

Post by hayasidist »

yeah - there was a flurry of activity on nested smartbone control a couple of years back -- e.g. one SB moving another SB that moves a third SB … or SB1 moves a target bone that SB2 follows … or layerscript that tracks SB1 and moves SB2 … etc -- bottom line: it doesn't really work.
Daxel
Posts: 967
Joined: Wed Mar 27, 2019 8:34 pm

Re: Bone that moves another bone that moves a third bone

Post by Daxel »

Thank you for your answers. If you guys don't know how to do it is probably not possible ;)
User avatar
hayasidist
Posts: 3492
Joined: Wed Feb 16, 2011 8:12 pm
Location: Kent, England

Re: Bone that moves another bone that moves a third bone

Post by hayasidist »

… just because an approach wasn't found back then doesn't mean there isn't one... :wink:
amanandink
Posts: 252
Joined: Wed Feb 13, 2008 10:28 pm
Location: Kilkenny, Ireland
Contact:

Re: Bone that moves another bone that moves a third bone

Post by amanandink »

depending on what you want to be able to do with the 3 bones, I have had some success in the past with mixing smart bones and angle control
B1 (SB) - SB drives -> B2 (SB) - angle control drives -> B3 (SB)
this method does mean you loose manual control of B3
User avatar
Greenlaw
Posts: 9191
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Bone that moves another bone that moves a third bone

Post by Greenlaw »

I agree with Jeremy. Nested controls are good when you just want to keep the controls simple and your characters have a limited range of expressions by design, but on the other hand, it can limit the possibilities when you want to go beyond that range.

For example, sometimes I'll use nested Smart Bones for eye controls: one Smart Bone to open and close the left eye, one to open/close the right, and a third to drive the first two bones to open and close them together. But then it gets complicated when if I decide to add bones to control each eyelid separtly so you can so 'smile' closed eyes and 'sleepy' closed eyes, or to do partial positions 'suspicious' eyes or invert those settings for 'bored' eyes, or completely different settings for each eye. (We did a lot of this stuff for Boss Baby.)

After a while, I decided that it's really not so hard to control the Smart Bones directly to get exactly what I want from the character. :)

(Tip: Give all your bones short and easily identifiable names and enable Show Label for the Smart Bones. Even if you're the only person who will animate the rig, someday you'll be really glad you did that.)

BTW, a while ago, I had a rigging situation where I found I could control an unresponsive bone with a Smart Bone if I kept it 'active' in the Timeline. I think I did this by applying an otherwise unnecessary Target bone. Sorry, I don't recall the details and it might also have been an unusual circumstance, but I usually document weird stuff like that so I'll see if I can track down the info.
Post Reply