A Stretchy IK

I have been helping a co-worker learn some rigging techniques, and since I'm essentially making tutorials, I figured I might as well post them for others to benefit from as well!  Today's topic is how to make an IK limb stretchy.

The basic idea is that we will measure the original length of the IK from start joint to handle, and any time that distance increases beyond its original value, the bones of the IK limb will scale to make up the extra distance rather than rotating beyond what makes sense (the cause of popping).


Let's dive right in!

Little Maya Cheaters

I've been known at my various places of employment for always looking for ways to cheat. Call it laziness if you like, but I've always believed in working smarter rather than harder. As a result, I'm frequently whipping up little scripts to speed up the workflow of my projects or to save my keyboard from repetitive use damage.

In maya there are a dozen or so core little scripts that I come back to over and over and over again. They just keep finding new ways to be useful. I've shared one or two with my co-workers and friends as the need arose, but I'd never really sat down and organized the lot of them for popular consumption.

Well, that's all changed now. They're free to download and use as you like, but please don't redistribute them.

Here's the overview of what's included:

Joints and orients and iks, oh my!

A lead rigging position in a decentralized studio means lots of emails about the proper way to do things. Here's one more I shall share with you! Kernels of wisdom about joint orientations (and how you shouldn't forget them) as well as a couple of comments on quadruped rigging.

Eclipse as a Maya IDE

I've been a hobbyist programmer for over a decade (damn, has it really been that long already?) and by necessity a semi-professional scripter for a little over 3 years. For the vast majority of that I was perfectly content to use an advanced text editor. As long as I had my color coding and and the occasional bracket mis-match highlighting, I was set. I even went so far as to program the entirety of my genetics sim game in SciTE.

Only a few months ago did I decide to finally see what all the fuss was about with IDEs. It took a day of tutorial diving in order to get Eclipse complete functional and communicating with Maya, but boy was it work it!

I set out this morning to put together a small stack of my tiny tools that my friends could download and benefit from, but instead of fixing one minor world-parent bug like I was supposed to, I felt the urge to praise Eclipse somewhere. And hey, it's Saturday. I might as well celebrate. ;)

Clean rotate values from your FK controls

Here's some basic rigging info that my coworkers needed.  As long as I put the effort into collecting it, I might as well share it with others too!

A lot of higher level rigging problems, particularly in the set-driven fixes area, can be avoided if your basics are solid.  While its amazingly easy to make a basic rig that moves things and appears to work, making one that will have clean values computed quickly, and thus make higher-level rigging easier, requires attention to some details that can be easily overlooked.