Better Living through Inverse Kinematics

Since we’re keeping it simple with the animated enemies in this project, I briefly thought I could achieve everything I wanted to do with simple bone rotation keyframes–this looked bad, took too much effort, and was just wrong.

My first couple of test poses were easy with simple rotation keyframes, but I thought it would be fun to import a video clip of someone doing something simple (I’ll reveal what I used on Friday) and see if I could get our enemy to do it side by side. Hashtag marketingBrain. This turned out to be a worthy test, however, because it revealed that this simplistic animation philosophy was going to cause a lot of pain when I wanted to do animate simple movements like crouching down and bending the knees a bit. The problem, if you’ve never tried this, is that grabbing the parent bone and just moving the character down a bit will simply drag the entire model down through the ground, then rotating the legs and feet back up into a believable position is actually crazy difficult. Far more difficult than it would be to set up Inverse Kinematics constraints.

I didn’t really remember the difficulty level of this task years ago, so I certainly didn’t know what I was in for in Blender 2.8. I did a quick search, and the results for any closely related search term were overwhelmingly skewed toward a pair of videos, the first of which promised “Inverse Kinematics in 2 minutes!”

And you know what? It worked almost perfectly! There was a little more to it than this because the first video only set up a leg for very natural movement. But the second video ran through setting up the same constraints for the arm and showed the shortcuts for mirroring the setup to the other side of the body.

I was concerned there may be more to it before I could make my model crouch down somewhat naturally, but there wasn’t. I was done!

My model is now posable with ease. I’m still going to run through that video mimicking exercise because I think it will be a good way to get acclimated with the graph editor and the dope sheet. I’ll show this off a bit, then I’ll set about creating a couple of animations I know enemies in the game will need. After that, we’ll see about using them from the Unity side at a moment’s notice.

Facebook Comments