rigging character for squash & stretch animation
 

hi

anyone know how / the best way to rig a character so that you can get nice squash and stretch animation?
I've looked at a couple of the rigs in the alias extras cd that came with my maya package but i'm not convinced they're very intuitive to animate.

The Nino rig (for those who have seen it) does a good job of squash and stretch but you can't rotate the spine (bones), and have to MOVE the handle instead to pose the spine. Not sure if i'd like to animate in that way...

Can anyone tell me if squash and stretch should generally be applied to the bones (joints) themselves in a rig?

Here's a list of all the methods I've tried so far:

1.
Simply moving a joint in the skeleton – will stretch but won’t retain volume (ie. stretch but no squash)

2.
SDK scale axis of a bone inversely proportional to other 2 axes (of the bone). Problem: the scale of the bones itself seems to work ok but does not translate well to the skin. (Get funny boxy deformation in the shape of the joint)

3.
Cannot apply Squash deformer to a bone.

4.
Use SDK to make stomach bulge as bones are scaled down – but this is not really “squash and stretch animation” - surely there must be a more intuitive way of doing it?

5.
Tried to turn Off scale compensate for just a few bones (eg) in the spine and not the whole chain… But can't seem to do that. Once you turn it on for 1 bone, you can't stop the effect from transmitting to the rest of the hierarchy below (even if you turn if off again on the other bones)??!!

any comments?

LisaC

theres some good tutorials here, even the one you want. The one you want is "Elastic Foot using Expressions".

http://student.vfs.com/~m07goosh/rig.../freestuff.htm

hi peltra

hey those are great tuts! thanks! just what i was lookin for...

Leese

thank for both of you ... that is what i am looking for too.
give us somes news about the result of yours test Lisa.

bye.
Laab.

No problem mate.

hi guys

those were great tuts! went thru a couple of them. the squashy-stretchy rigging one works fine (except I stalled for awhile at the middle coz they left out 2 points regarding linking (here they are - i tesetd it out and it works now)

- Create the ankle’s IK (ikHandle_ankle) not from the hip as per usual (since there is already one there for the IK leg chain) but from ankle2Control (ie. so the chain ‘continues’).
- Link both locatorAnkle and ikHandle (the one created earlier from the hip) to ankleControl.

Everything works fine except that I am not used to animating arms with IK. I would much rather use FK if i can help it.

Legs work ok. One slight problem is that you can't get them to rotate from the hip - with IK set ups, you have to position the foot first, then rotate it to the correct angle after. That sucks. I tried doing a few different links and constraints to have it rotate from the hip but none were successful. or rather - they mess up once you set a key on it :)

anyone know how to to squashy stretchy arms without IK? I suppose i way is to just used SDK on the scale of the bones.

anyway... my 2 cents :)

cheers
LisaC

please give me free tutorial site for maya 3d

hi lisa,

for hip-rotating the leg thing I can say that a polevector-constraint allways did a real good job for me. and concerning the arm-setup -> you might think about switching between FK and IK.

there´s an awsome guy showing some stuff at http://www.theanimator.co.uk/


cheers dani

thanks dani

:)