We reinvented game animation (Patreon)

By Salireths

A lot research and development has gone into this new animation tech, all to achieve an unprecedented character customizability and player-driven body control (including control over individual bodyparts), unlike anything the Furry Fandom has ever seen before!

But first, let me explain why it's so important that we chose to animate characters procedurally, instead of sticking with the original plan to do it how the most other games do it.

The traditional way

The traditional 3D animation is very limiting: say, you've made a character and animated it. If after that you decide to change the proportions of that character (like making their legs longer and/or spine shorter), you'd basically ruin all their animation - the limbs will be in wrong positions, feet would go through the ground, etc. Even if you retarget animations with traditional methods, there is still a lot of problems. 

Most game devs produce one skeleton for multiple characters, making creatures look visually different, bit still having the same proportions - just so they can share animations. (Keep in mind, they can be different in size, just as long as they are scaled uniformly).

Here is an example from Guild Wars 2, different mobs that re-use the same animation skeleton: Skales, Skelks, Vampire Beasts. There are plenty more examples in that game due to sheer variety of killable fauna (and skillful artists) they have there.

This was the same approach we were going to take before the recent release of Unreal Engine's Control Rig, which has opened a door for new exciting opportunities. This is when we decided to overhaul our character/species creation system to take advantage of it.

If we were to attempt to do a species editor without it, such a vast choice of different bodypart options, proportions, postures and leg configurations, would simply drive any animator insane. Thankfully we don't have any 3D animators on our team (thus their precious sanity can be preserved). Who we are instead is technical folk, ones who are eager to take their trusty wrenches, keyboards and Wacom tablets to figure out a solution to a problem.

The procedural way

Our approach was to create a new, universal format of animations that work regardless of body proportions, species, and would even be shared between bipedal and quadrupedal characters.

It's not something magical, and clever people at Rockstar (remember the seagull meme?) and Ubisoft are doing something similar for their games (here is a GDC presentation of their IK-Rig system, check it out even if you don't know anything about animation - it's pretty well presented and has a lot of video examples).

And, fortunately, we don't have to recreate what multi-million corporations can afford - now, powered by Control Rig system we could do it too! Fortnite uses this exact system already for the Wolf and Fox skins, their digitigrade legs would not be compatible with all the fancy dances otherwise.

As of old animations we'd already done, we will just convert (retarget) them - nothing is wasted! We can do the same with mocap data we might get our hands on, since now animations can just be imported from any skeleton, even if it’s a human or any other animal.

Meet the Team

Here are various skeletons (remember these still just drive the motion of character models and can be shared between) that I'm going to be referring to down the line.

The Bipedal-Upright skeleton
Our old skeleton with all the animations we've had thus far.

Mixamo skeleton
For free human mocap animations we only used for testing, by Mixamo

The Abstractor skeleton
The middle-man, the translator, the backbone system that makes it all possible.

The Creature skeleton
Our new universal creature, one that is designed for changes of proportions, postures, and attaching various bodyparts of different species.

Abstraction Process

First, we take our old Bip-Upright skeleton and translate its old animations to Abstractor via power of math.

Abstractor doesn't have elbows or knees, and has very little bones in general - making it move like something from Minecraft. "How is this better?" - you might wonder. Think about how VR games manage to animate your virtual avatar by only tracking your headset and controllers - this is similar, only Abstractor records a bit more information (like full-body tracking). It doesn't need to know where the knee or elbow is if it knows the direction of it.

Here are some Mixamo (human mocap animations) to Abstractor conversion experiments:

It also doesn't matter If the source (or target) character is standing on its toes like a dog (digitigrade) or its heels like a human (plantigrade) - the Abstractor doesn't need to know that. For example, for the legs, all it knows where the point of contact with the ground is and what is the forward direction of the leg. Same principle applies to other bone-chains like arms, spine, neck, wings, tail.

This information is all we need to recreate animations in the next stage.

Recreation Process

So far we've only abstracted the animations, but in this format we can't use them in a way that would be visually pleasing. We need to apply it to the a skeleton (and thus to any model we wish). It also doesn't matter what customizations the player has selected for their creature, what size, posture, height or configuration of the legs.

Recreated walk cycle on Creature skeleton:

Each character archetype has a lot of math-heavy rules defined on how the Abstractor is mapping the motion to the actual rendered Creature with some tweakable parameters.

These parameters, for example, can modify the walk cycle so the character makes smaller or bigger steps, or sways hips more. We can make them crouched because the ceiling is too low. We can put one character's hand onto (or into) another character's butt - exactly where a horny player has designated. And we can make them start limping after they've been kicked for such impudence. All without having to make more animations!

Here is how recreated motion looks (we used an unfinished proto-shifter species for the preview):

Onwards!

While it all might look too-good-to-be-true, some kind of dream-tech. But the fact is, it's there already. We are just a tad bit away from making it be fully integrated with the rest of our character systems.

Of course such tech has its own minuses, but overall, let's just say that our game is going to have… A very unique and sensual benefit from it, something we're going to talk about very soon…

With lots of Dragon Love
         - Salireths.