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WIP #12 Writeup: Microrigging
🕑 Added 2021-11-25 12:14:51 +0000 UTCHey all! Time for another workflow writeup - this time I'm going over an extremely important but often overlooked tool in the belt of an animator: microrigging. This is the process of creating new, smaller rigs on the fly specifically for one shot you're working on to acheive a specific movement more easily. This isn't a technique that has a particular name in most studios, it's just something you're expected to be able to do if needed.
Microrigging can be very simple, maybe you need a character's mid-shin to rest on something, so you set up a couple of empties and constraints to jury rig a kind of auxilliary IK to handle that. It can also be more complex, like the entire extra armature I created for rarity's skirt here, to get it to stretch correctly between her legs:
The important thing is to not limit yourself to what the rig you already have can do - it's impossible to create a rig that can cover all possible movements that a character could have to perform! At the end of the day it's always going to be the animator's job to fill whatever gaps emerge.
Why go to all the effort of creating a whole new rig? The bane of any animation project is "counter animation" - manually offsetting one part of a rig to couter-act the motion of another part of the rig. Not only does this take much longer than just making a sub-rig, it also makes your animation fragile - making good animation requires many revisions and reworkings, and every time you change it you have to completely re-do all your counter animation. No fun for anyone. Taking a while to make a system the actually correctly handles the motion means it'll work not just this time, but in all future revisions.
this skirt is a perfect example! It's also a real pain. I need to be more careful about taking on long, tight skirts. The way they have to wrap around two independently moving legs is extremely complex to manage.
What I've done here is to add additional bones parented to the thighs of the parent rig that stretch across the two legs and back up to the fold at the hip line, defining a sort of "plane" where the front and back faces of the skirt should go. it's not perfect, but it does what it needs to do. That's the core of microrigging - you need to identify the difference between kind of motion you need and the kind of motion you're getting, and use the rig to correct for that. if it's not exactly 1:1 that's fine, as long as it's the right kind of motion, you can correct the rest with other techniques. here are the shape keys on that skirt:
Yeah it's a lot. Notice how I'm still only using one tool for one job - each shapekey only applies for 10-20 frames and solves one specific problem, and is labelled with the frame it's correcting. This helps avoid getting deformations lost in the pile and chasing yourself in circles correcting your corrections.
here's another example!
A much shorter skirt is easier to handle. Here I identified not just how the skirt behaves in general, but the specific kind of motion it would have to be undergoing and built my micro rig to handle that specific task. in an animation where the skirt is flapping less from side to side, but instead being removed or pushed around, a completely different setup would be appropriate. It's all a case-by-case basis!
