Squash & Stretch acting oddly

[Maestral]

I've made a quick test and ran into this:



- 0 strength on all bones
- point binded rig / each part is a separate layer
- leg bones have Squash and Stretch & max IK stretch enabled (150%)

so...

Why are the legs detaching from targets?
Why are the legs switching/aiming off of the targets?
Why are the legs falling/passing down the targets instead of squashing?

I haven't used Squash & Stretch much, so I guess I'm missing some basic stuff here.

* Pardon the broken link. It was a temporary link, but the image below shows the issue.

[synthsin75]

Targets do not ensure you cannot pull the skeleton too far away from the target. They just try their best to keep pointing at the target.
Suddenly jumping off the target looks like the bone stretching is changing the geometry enough to throw off the calculation. I'd have to see a file to diagnoses any further.
Stretch & squash only squashes when you manually scale the bone down, and IK stretching doesn't natively include shrinking. Since the leg bones can't shrink on their own, they go below the targets.

[Maestral]

Thought the target would hold the legs while they stretch to some extent, and then separate. I'm dragging the whole idea from memory, as I believe I've seen something similar in one of the tutorials or webinars. Would a higher % for SS solve this, or perhaps a different (flexy,layer bind...) rig would enable such behaviour?
Now that you've mentioned it- the origin for the legs is set on the hips, the outer upper corners and most likely causing the jump.
Thanks for the reminders. False expectations got me stranded x)

Thanks, Wes

[synthsin75]

Thought the target would hold the legs while they stretch to some extent, and then separate. I'm dragging the whole idea from memory, as I believe I've seen something similar in one of the tutorials or webinars. Would a higher % for SS solve this, or perhaps a different (flexy,layer bind...) rig would enable such behaviour?

Squash & Stretch just determines how the art is warped when the bones scale. It's Maximum IK Stretching that determines how far the bones, themselves, can stretch before pulling away from the targets.

[Maestral]

Apparently, it was all about that particular rig/ging. I made another simple test in a new file, and voila...



I've tried modifying parenting, binding, and several different settings, but to no avail. And once I removed the Angle constraints for those hip bones, it all worked as expected.

My idea was to have just the legs affected by squash&stretch, so to preserve the character's design (a flat line at the waist and legs in the given positions), I had to add another bone, from the root bone. I've tried with just 2 bones per leg - 1 from the root, aiming for the knee and the 2nd one as a shin but to no avail again. Manual adjustments were also required.

Even if I remove the hip bones and bind the waist and top of the legs to the root bone - these additional bones (1 per leg) are still needed. The thing is, once the stretch begins, all of the proportions are gone and have to be adjusted manually. Since the SS is not actually necessary in this case and since I'd have to adjust the deformations manually - why bother adding Max IK stretch at all? What am I missing?

*** solution ***

Adding a pin bone between the hip bone (with constraints on) and the upper leg bone solves the issue.


* I believe it's not shown, but I've edited the message several times. Which, I believe, can be seen x)