Kinect + AE: A better way to control the puppet’s head

So in my Kinect + After Effects tutorials I offer a couple ways to rig the puppet’s head, but neither one is an ideal solution: the first one leads to occasional face-stretching and the second to increasing the manual animation workload substantially.

But there’s a better way! Put the anchor point in the center of the face, and attach the position keyframe to the Head control point. Then apply the following expression (based on one originally found here) to the rotation parameter:

this_point=thisComp.layer("Spine").effect("Head")("Point");
that_point=thisComp.layer("Spine").effect("Neck")("Point");
delta=sub(this_point, that_point);
angle=Math.atan2(delta[1], delta[0]);
ang = radians_to_degrees(angle);
(ang+90)%360+transform.rotation

Now the head will rotate to match to the angle formed by the head and neck points, but without the weird distortion the Puppet Tool can cause. You can tweak the head’s attach point by shifting the anchor point.

Kinect MoCap Animation in After Effects — Part 4: Rigging a Digital Puppet

Yes, it’s the part you’ve all been waiting for: it’s finally time to set up your character layers!

This was originally going to be in Part 3, but there are so many steps I realized I needed to break things down a bit more.

Bite-Size Jurors

I’m working on a series of films about juries at the moment. They should be pretty fun to do (I get to animate trial by ordeal, for one), but there’s a lot of character work and not a lot of time. Thus, digital puppetry.

I was hoping to work with After Effects’ extremely fun Puppet Tool, but the results I got while experimenting were just a little too squishy for this project. (Anyone know some tricks for getting convincing, not-too-exaggerated motion out of it? Even liberal use of the starch tool seemed unhelpful, and I couldn’t for the life of me figure out a way to make elbows and knees bend properly.) So for the moment it’s back to IK rigging — and a lot of carefully placed anchor points.

I’m much more satisfied with the results, particularly now that I have a keyframable checkbox parameter that switches the bend direction of the joints. In plain English, I can make someone’s elbows bend both ways — e.g. a character can go from having their hands on their hips to picking something up off the table next to them with very little trouble.

Creating the jurors themselves was a lot of fun — the characters need to function more as archetypes than individuals. The result: a wide range of ages and races and a complete lack of faces.

I now present… my little jury guys (and girls!):

Warning: Do Not Eat.