Miscellaneous

Humpback Whale

Responsible for the sculpt, model, textures, and rig.

Quads 4.1k

Total triangles 8.3k

An early project.

We wanted a realistic humpback whale that quietly swam past people’s screens. It was a good candidate for the app at the time because we didn’t have to worry about floor tracking for it.

Animations created by Liz Walcher

Chubby Swallow

Responsible for model, texture, rigging, and animation

Quads 486

Total triangles 976

When birds flap their wings, it’s good to exaggerate the motion of the flap. It can be very easy to make the motion feel stiff by not bending the wings enough. By treating the wings more like paper and having the ends resist the movement near the shoulders, the flap has more impact.

I didn’t have much experience animating, but I had a pretty good idea on how to set up dynamic joints. I wanted to see if I could set up controls that would use dynamics to simulate movement of the wings bending without having to hand-animate everything.

Dynamic driver

The general way this works is that there’s two bone chains. In terms of hierarchy, it looks something like this on the wings:

controls —> fk bone chain —> dynamic bones skinned to the mesh

The bones that are skinned to the mesh are dynamic using a spline curve that has hair dynamics on it. That curve is driven by a separate drive curve that is controlling the second bone chain. By setting how much the dynamic hair curve follows the drive curve, we can choose how much dynamic effect we want. This means that it’s totally possible to just animate the wings normally without using dynamics.

In the video on the right, the bones you see are the fk bones that are influencing the dynamic bones. The extent of the influence is less than one so the dynamic bones don’t follow the movements entirely. That’s what gives us the nice bending instead of a stiff wing movement

Postmortem

I think if I had a choice again, instead of using two bone chains and having the skinned bones be dynamic, I would experiment with making a system closer to the classic 3-bone chain ik-fk switching. Where the dynamic bones and the fk bones both constrain the skinned bones to varying degrees according to a float channel box attribute. This might give me more controllable results