Rigging a worm in AS10

[Víctor Paredes]

Hi, yesterday I had to animate a worm for a videoclip I'm working on and got this idea:

It's a combination of target bones and squash and stretch scaling. The vertical bones are parents or targets of the horizontal bones, so I just move that vertical bones to animate the worm. Since the horizontal bones are squashing and stretching, it really helps to give the sensation of a moving internal mass.
I just thought it's a cool rig, maybe it can be useful for you in the future, you never know when you will need to animate a worm

[jahnocli]

Ha ha! Terrific idea! Makes me want to animate a worm right now...

[heyvern]

Awesome!
have to try this out. I am thinking this could work for limbs and body with some additional rigging. Will have to experiment.
My thought would be "sections" of "squash and stretch" within body parts that can also be rotated.

[braj]

I'm so confused! Can you show how the parenting is set up? My attempt is a mess. Thanks!

Nevermind, I figured out that you don't use a parent for any of the control bones, and of course not the target bones. This is a very nice trick.

[synthsin75]

Wow, very cool rig.

[sbtamu]

That technique looks a lot like the flag you made a few years ago. Thanks for sharing.

[synthsin75]

One question. How are you getting the bones to squash?

[funksmaname]

Really nice effect Selgin.
Synth, the linking (hidden) bones have squash/stretch scaling enabled I presume, so as the control bones get closer or further the middle ones squeeze and pull

[Víctor Paredes]

One question. How are you getting the bones to squash?

It's a little trick. The bones have Squash and Stretch scaling activated, but that only works for stretching. By default, if the target is close to the bone, the bone never goes lower than its normal scale.
To "activate" the lower scale, in frame one I scaled the bones to 0.1. Then I assigned a Maximum IK Stretching to 30 (or even more). That way, the software assumed the "normal" scale was that 0.1, and then stretched the bones to get the target. So I had freedom to move the target and get Squash and Stretch scaling from 0.1 to 3 (0.1 * 30 = 3)

[Víctor Paredes]

That technique looks a lot like the flag you made a few years ago. Thanks for sharing.

Yes, to animate the worm crawling I used that same principle

[synthsin75]

One question. How are you getting the bones to squash?

It's a little trick. The bones have Squash and Stretch scaling activated, but that only works for stretching. By default, if the target is close to the bone, the bone never goes lower than its normal scale.
To "activate" the lower scale, in frame one I scaled the bones to 0.1. Then I assigned a Maximum IK Stretching to 30 (or even more). That way, the software assumed the "normal" scale was that 0.1, and then stretched the bones to get the target. So I had freedom to move the target and get Squash and Stretch scaling from 0.1 to 3 (0.1 * 30 = 3)

Brilliant! That's exactly the part I was missing. Thanks, Victor.

[braj]

I turned my worm into a walrus, it works great

[heyvern]

One question. How are you getting the bones to squash?

It's a little trick. The bones have Squash and Stretch scaling activated, but that only works for stretching. By default, if the target is close to the bone, the bone never goes lower than its normal scale.
To "activate" the lower scale, in frame one I scaled the bones to 0.1. Then I assigned a Maximum IK Stretching to 30 (or even more). That way, the software assumed the "normal" scale was that 0.1, and then stretched the bones to get the target. So I had freedom to move the target and get Squash and Stretch scaling from 0.1 to 3 (0.1 * 30 = 3)

That's the trick I have been using to experiment with character rigs to get more "flexibility" with squash and stretch of limbs.

One "extra" trick I use is to copy the bone scaling to frame 0. This creates a scaling bone "offset". This way I don't have to worry about the extra key frame on frame 1. Some times that frame can get deleted if I don't pay attention . Bone scaling is not supported on frame 0 so the only way to "scale" a bone on frame 0 is to copy and paste the scale key frame from another frame.

This has drawbacks but it keeps all the set up on frame 0 where I like it. Scaling limbs for characters this way does work but it can be a bit weird depending on how the layers are drawn.

[ARTzuza]

Hi Selgin,
so interesting. Please can you show us the bone setup (parents, targets) with an ".anme"?, i want to study it because i have been trying to replicate this rig for to learn, but i don´t get it. Please can you submit a .anme?

[Víctor Paredes]

Hi Selgin,
so interesting. Please can you show us the bone setup (parents, targets) with an ".anme"?, i want to study it because i have been trying to replicate this rig for to learn, but i don´t get it. Please can you submit a .anme?

No problem
https://dl.dropboxusercontent.com/u/544 ... m_rig.anme