Crafting character animation

Kiel Figgins demonstrates and explains the key techniques in creating dynamic, fast-action character animation

This video shows the boards provided by the client and their initial 3D blocking (the sepia tone). You can see how a T-Pose character doesn't convey the scene very well, plus with the uninformative environment and viewport clutter, this meant their blocking had to be redone from scratch. You can see where I picked up the shot around the 10 second mark. As the ideas started to take shape, the shot grew longer and more story points were added. The following tutorial is based around that process.

Showing the stages of a fast action shot

Overview

One of my favorite types of animation is fast action and acrobatics. These shots have so much energy and excitement that keying the flow and poses really lets you push what the character's capable of.

When I'm assigned a shot like this, my typical approach is to make a proxy of the character and environment, and animate the entire sequence on those proxies first to get the flow. Since these shots are more about the transfer of inertia, I don't worry about the poses until later. These shots typically require a lot of iterations, revisions, or complete overhauls to get them to work in the edit, so speed and playback speed is a must. Working with proxies allows for timings to be made in the viewport with minimum playblasting, while keeping the keys clean enough to slide around the major actions.

On another level, having the core motion on a basic, non-descript, character allows the viewer to project their own mental image of the character onto the action. The motion doesn't look "wrong", since it's not a real character. This approach stems from getting an idea across in instances where stepped poses wouldn't clearly be understood or applicable (Previz, motion graphics, game engines) or when working with a client that is unfamiliar with stepped poses and may view them as a compression error, glitch or mistake.

Cube jumping through buildings

Cube jumping into a moving car

A common practice is cutting up the high res mesh of the character and using those pieces. With that approach the viewer will keep looking at how the mesh is chopped up, and worst of all, the static expression on their face. Having basic cubes allow you and the viewer to focus solely on the motion, without the distractions of penetration, bind issues and expressionless faces.

Benefits

There are several benefits to this approach:

Separation between timing and making beautiful poses. Focusing on one element at a time leads to a more concise final product. If I have to worry about the poses at the same time as the flow, I typically get bogged down. Also, due to the highly iterative process of fast action shots, creating rapid versions that can be seen together in context of one another (or in the edit) is desirable. If the flow, timing, or staging needs to be changed, having the shots in a malleable state reduces time lost crafting poses that may not be used or scrapped entirely.

Able to hand over the blocking scene to other Animators without clean up. Every Animator will set a pose differently with the same rig. Since the blocking has been done on a proxy element, the Animator, either in house or remote, can set the pose as they see fit. The Animator will have the proxy animation to refer back to, also, if they've referenced in the blocking scene, the blocking can be updated later as needed. There becomes no need to delete keys, work off existing keys, or have multiple references of the same character. Often times, the final rig isn't even completed at this early stage, so this allows animation to start while the rig is in development.

Final assets, such as models or rigs, are not needed for animation to begin. Often a Director will have an idea of a sequence or moment that he wants to see quickly. It may be a new addition or a change in an existing shot. Being able to quickly block out the key elements not only shows that an idea will or won't work, but can provide a base for scale for modelers, and range of motion of the character for the Setup Artists to have a heads up on.

Less personal connection to the poses. The mentality of adjusting 10 controls to change the pose is far more forgiving, compared to all the controls of a full rig. Plus, if animation needs to be duplicated, offset or transferred to another character, there are far fewer controls to worry about.

Able to determine if distance travels is applicable to the character. Often Animators will "skate" a character in T-pose around a scene to illustrate him walking or running. Unfortunately, this does not tell the viewer if the legs are going to be moving too fast. If they are, the distance traveled will need to be adjusted, either in the type of locomotion or by changing the environment. Both of those can drastically affect the mood of the shot, imagine a femme fatal striding through a doorway, now imagine her having to jog to cover that distance.

Animation blocking is more descriptive if someone else is doing the camera or building the environment around the animation. Having the arcs and full frames of motion is far more useful if someone else is doing the camera work for your shot. Knowing where the characters are in space affect the composition more, than the intricacies of the pose. Plus, if a character is running through a city, the environment artist will have some idea how much of the street to flush out and what elements the character or camera gets close to.

Stepped poses in game engines read as dropped frames. A stepped animation in a game engine can read as many things, such as a playback issue, export error, frame rate drop, or a heavy compression setting. They also are not as useful to designer that may need to work with blending the animations or working with it for scripted events.

Setting up the character

Building a proxy of your character should be a fairly short process. It's all about approximation, so leave out: hands, fingers, feet, toes, face, and accessories. If your character has a defining feature, such as a large jaw, and is biting in the animation, proxy that in as well. The goal here is get a character that is quick to animate and playback in real time in your scene

Number of controls per layer

Number of controls per layer

This character would have no controls, only parented polygons, all channels locked if they cannot be keyed (typically scale and visibility), and all placed under a single group. The proxy is typically made of separate poly cubes, roughly sized and shaped to the limbs of the character, with pivots at the logical bend points (knees, elbows, etc ). If you can match the pivot position of a control for the proxy mesh, that's a bonus. If you plan on transferring keys, be sure to match the rotation order of the control. Don't spend too much time here, since you'll be redoing those poses on the final rig anyways, so it's best not to noodle. To save on modeling more cubes, I typically allow translates on the upper arms, legs and head to act as clavicles, hip and head tilts.

Hierarchy of proxy character

Hierarchy of proxy character

Blocking the scene

Now it's time to start blocking your scene. You should have some sort of direction (boards, written or verbal description) of what needs to happen in the shot and roughly how long it should take. If this is a personal project, you may only have the story points you want to convey.

Before you start laying out the shot in 3D, map it out on paper. Typically I'll have clipboard of loose leaf 8.5" x 11" white paper that I can scribble on. I'll write the notes, story points and frame range on the corner of the page as a constant reminder. The notes remind you of what the character should do or not do, story points, overall goals, and a rough frame range to prevent you from getting carried away.

Initial sketch for flow/path of the dragon

Initial sketch for flow/path of the dragon

While you're mapping out your ideas, don't use the same motion all the time (such as a flip), there are so many ways to make it interesting, so mix up the moves by adding twists, curls, and off axis motions.

Also, don't stop at your first idea, do several sketches of other ideas. The main reason for this is that your first idea is typically everyone's first idea. Thinking more about the sequence and exploring other options will allow you to infuse more personality and uniqueness into the shot. Even if you do end up going with your first idea, the continued brainstorming should allow you to add in bits and pieces from your other ideas to make the first one that much better. Pulling from multiple sources will help with this brainstorming, so I'd highly recommend looking at comics, video games, movies, and real world examples (parkour, karate, dance, extreme sports).

Photo reference/inspiration for poses

Photo reference/inspiration for poses

If you find yourself getting stuck, a good approach is "Do what you know". If you know you're character has to be standing on a ledge at the start of the animation, hanging from a helicopter in the middle, and falling into a ravine at the end, map those key poses out with an interesting camera angle for each. From here, filling in the blanks of how he gets from the ledge to the chopper is far more straightforward.

When you start transferring your 2D ideas into 3D, it's likely that you'll need some sort of environment. Start by making proxies of the key elements, worry about the background and finer elements once the shot is further along. The goal is keeping the scene as light and fast as possible, so cubes and planes to illustrate the key environmental elements, such as building and the ground plane. Next, create your camera and set your frame range. If you have the option to adjust the environment, take advantage of it. Sometimes you can get a much better animation by moving the set pieces around. This can make jumps more dramatic or parallax more apparent in chase scenes.

Basic environment

Basic environment

Animation layout

With your scene set up and idea in place, start animating your character through the scene, not worrying about the camera or framing at the moment. Animate the body first, to figure out where your character needs to be in space. Once you have the character hitting the key points, start working the other elements up at the same rate: rough in core action, then base camera motion, adjust the environment if necessary, refine the action, repeat.

You'll realize pretty quickly that you'll spend less time on creating poses with your proxy guy, and start focusing more on the flow of the entire scene. So long as you work the elements up together, you'll be able to solve problems that may come up much sooner and with more flexibility than if you started making poses right out of the gate. Perhaps your environment doesn't support the camera angles you had in mind, or your character is too small to cover the distance in the shot.

Here are some additional tips for the layout stage:

Set minimal keys when your character is jumping or airborne. Since he'll be going in an arc, you should try to keep it at 3 keys: jump, peak, land. Break tangents on Translate Y to get the trajectories and a single Translate Y key at the peak to determine the height. Translate X and Z would only have two keys, one at the jump and one at the land, since he wouldn't be able to change direction while airborne. Since nothing is acting on the character except for gravity, this approach works nicely. It also allows you to adjust the jump very quickly (landing in a different place, making the peak higher or lower, etc).

Animation curves of proxy character

Animation curves of proxy character

This stage is all about approximation so leave out wrists/faces/accessories and don't worry so much about feet slipping or penetration.

I try to keep my timeline for the entire animation open so I don't noodle too much in one area. In contrast, when I do the final animation, I typically polish in 12-40 frame sections. However, when I'm laying out a scene, I like to keep the entire flow in mind.

Use all three axes in your motions. Having a character run in a straight line or dive out of the way at a perfect 90 degrees is boring. Keep it interesting and more natural by going off axis. This also stands true for your motions, instead of doing a forward flip, the character could do a barrel roll or hands free roundhouse.

Ready for full animation

When you're done with the proxy layout and approved to finish the animation with the full rig, start by selecting your proxy character and creating a reference layer. Set this layer to Transparent. Now you can start keying the full character rig to match your proxy character's motion.

You'll notice your poses may not line up exactly (the curl of the body, how much you translated the shoulder/thighs, etc), but that's okay. The goal wasn't to focus on pose, but on flow. Now that you have the flow of the shot, the character world position, key pose timing, and an approximation for the camera, you can focus on the pose without focusing as much on the timing. Remember, the layout is a guide and is not set in stone.

Another use for the layout, is that you can refer back to the keys you set on the proxy objects, usually the body, to get the frames that you set key poses on. This a great starting point for setting key poses on the full rig. This is main reason I prefer having the previs done on a stand alone or separate rig. A clean rig can be brought in an animated atop the previs, without trying to deal with the keys that were previously set.

Also, you may find that you need to cheat motions when laying out a sequence, such as grouping the proxy character and rotating him to face a different direction. Since it is much faster to do this than it is to reanimate the action, having the final rig come in without this offset allows for the animation to be done cleanly, without the cheat. Now you can begin keyframing as you see fit and start to polish the details in the animation.

Proxy Character overlayed on animation rig

Proxy Character overlayed on animation rig

Here are some tips for polishing your animation.
• Work in small frame ranges, not the entire timeline.
• Key a pose 5-10 frames before the start of the frame range as if the action is continuing when the scene starts. This helps with first frame simulation on dynamics and motion blur. It also helps you mentally not start all your motions at the same time once the first frame starts. This is also true for the camera, having it already in motion makes it feel that much more intentional.

Conclusion

I use the cube to easily flush out the flow and motion of a character; to help find the right idea out of many. If you're doing a personal project and have a crystal clear vision of how the shot will look, then jumping straight into full body poses is an option. However, if you're trying to achieve the vision of someone else, typically the director in a production environment, the cube method allows for faster revisions and turnarounds with less lost work.

Related links:

Visit Kiel's website for more animation projects
Check out Kiel's other animation tutorials on the 3dtotal site
See our ebooks for more tips on animating characters

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