How do we inbetween?

Variable frame rate lets us animate more like a speed painter, suggesting rather then creating detail.

When I talk about interpolationless animation, the first question I usually get is something along the lines of, "My God, you're not posing every single frame, are you?"

To answer that, I’m going to bring up an animation example I did with a slightly older system. This system is the same one used on The New Pioneers, which is maybe half-way to the fully ephemeral and interpolationless workflow I envision.

This was a test Chris Perry (the director of the New Pioneers piece) and I did for Vintata Animation Studio, using background art by Jeet Dzung & Ta Lan Hanh . I also produced an animation demo, showing the animation process that I was using at that time sped up ten times.

Yes, I’m posing every frame--but with caveats. I have the breakdown tool to help me make in-between poses quickly, though it doesn’t work well for all poses yet (that’s a big goal for the current ephemeral rig system). But I’m also leaning on the NPR-rendered look of the shot to let me animate using a combination of 1s, 2s, and 3s, as a traditional animator would.

This is hugely advantageous for a variety of reasons. Obviously, it lets me make fewer poses! But it also changes the way the audience perceives the motion.

A great deal of the time put into CG animation goes into “polish,” the point at which the overall performance is set and the animator goes in to remove little pops, smooth out discontinuities of motion, and add little overlaps and weight shifts. For most fully-rendered CG this is a necessity--not doing it results in motion that pokes you in the eye with something awkward right when you need the audience to pay attention to the character’s emotions. And yet drawn animation doesn’t have the same problem--lots of great drawn animation has pops and wobbles that would stand out like a sore thumb in CG, and yet look perfectly fine in the drawn context. A drawn animator can hold a frame. A CG animator has to do a moving hold just to prevent the character from dying on screen.

I’ve come to the conclusion that this is a combination of a more graphic, less specific look--line art being about as graphic as you can get!--and the use of what I’m calling “variable frame rate,” ie. the mix of 1s, 2s, and 3s commonly used by drawn animators. I think that the key here is supplying the audience’s eye with enough information to perceive the important parts of the shot, but withholding enough information to allow the audience’s mind to fill in the detail that isn’t important. It’s like a painter suggesting detail with a few brush strokes instead of painstaking photorealism--frequently the more painterly approach will actually be more beautiful than strict realism, but requires far less time and iteration (but potentially greater skill to pull off well).

That said, variable frame rate isn’t always inconsistent with fully-rendered CG: Blue Sky’s Peanuts movie has a stylistic context that allows for both!

To some, this may make the interpolationless approach seem very niche--naturally, most CG productions are not going to use the combination of NPR rendering and variable frame rate I’m using here! But I’m not convinced of this--I think that this is a consequence of the way CG tools have developed, and that an interpolationless workflow would actually be very effective for a wide variety of animated productions with the right tools. And while the current workflow would not be suitable for full frame rate of very nuanced work, I’ve found it entirely suitable for full frame-rate action shots in the stylized context. Consider this shot from New Pioneers, done using full frame rate to accommodate the sweeping camera move.

I’m also using a “free” or “broken” rig, with only partial ephemeral features. Free rigging dates back to the Disney production Chicken Little in the early 2000s. The idea is that most controls just live in world space, and the animator is expected to place them wherever is appropriate for their pose directly. If you want an elbow to be somewhere, put it there. Don’t expect IK to do it for you!

I’m a big fan of free rigging, and I think it’s frequently the perfect manipulation method for the cartoony or semi-cartoony animation I want to do. Watching the video above sped up, you can see how my workflow feels more like sculpting the pose into place, then adjusting an armature or puppet. But it does come at a cost. As you might expect, if you have to place everything where you want it every time posing becomes much slower.

To combat this, Tagore Smith and Brian Kendall developed a “phantom manipulator” plugin for me, essentially an earlier implementation of ephemeral rigging in the form of Maya manipulators. You can see me using it several times in the video, where I grab several world-space controllers and rotate them as one. It made things a lot faster, but having the ephemeral behavior be part of a manipulator turned out to limit it. What if you wanted that behavior, but in the context of an entirely different manipulator--say, having the arms react with IK when rotating the torso? Building a manipulator-based ephemeral rigging system that could react in all the different ways an animator might want was difficult to plan for, which is why I’ve moved to the callback-based system I’m developing now.

It also has implications for the way the ephemeral rigging interacts with the breakdown tool. Here it doesn’t, and all interpolation within the tool is done linearly in whatever space the control is in, which is frequently world space. Using the breakdown tool for bigger, wilder movements would tend to react mangled breakdowns. The new system, on the other hand, will let you configure the rig however you want and will then use that configuration to make breakdowns. That’s actually the part of the system I’m working on right now, and hopefully I’ll have a new video to show of the new behavior next week.