So I think I'm going to shift gears here and post something I've been wanting to do since Animation Mentor released it's Animals and Creatures class (click here for details). I have a couple of projects that I'm working on, but almost finished with. I want to work a funny dialogue animation then I really want to do a quadrupedal animation of some kind of animal. My buddy at work sent me this link and it's really intuitive. It's a bit lengthy, but has some really good stuff in it.
Without further ado, here we go!
Getting StartedWith a media viewer that can scrub single-frame backwards and forwards, like QuickTime, you can watch the movement frame by frame. Drawing thumbnail images with directional notes helps you synthesize the information.
There are now lots of websites out there that put up live-action animal footage, such as the Rhino House human and animal locomotion website, which has a built-in player that can scrub their video reference material (click the image below to check out their website and viewer). Thanks to the internet, finding reference and getting into it to see what is going on is the easy part. The hard part is converting that information into something that makes sense to the animator and for the character that is to be animated.
1. Consider what animal most closely resembles the beast I need to animate.
2. Search for reference material. Here are the sources I find useful:
- Life drawing and observation
- Disney Animation The Illusion Of Life, Frank Thomas and Ollie Johnston, 1981
- Animal Locomotion, Eadweard Muybridge, 1887
- Video capture
4. Create thumbnail drawings to assist with my animation, including notes on direction and any unusual qualities I can see in footage.
The Four GaitsIn the course of my career, I've learned that there is a surprising similarity in how quadrupeds move, from species to species. Eadweard Muybridge's photographic works may be a century old, but they are still relevant and extremely useful.
In his introduction to Animal Locomotion, he maintains that most quadrupeds -- be they dogs, cats, horses or rhinoceroses -- follow the same footfall pattern. This is the order in which the hooves or paws strike the ground while moving through the various gaits. Where they differ is in the flexibility of the spine. Visualize a rhino running, as opposed to a cheetah. The exceptions, according to Muybridge, are elephants, and animals like kangaroos.
The four speeds of movement, or the four "gaits", are shared amongst most four-legged animals. Almost every quadruped walks, trots, canters and gallops, and their legs move in the same manner when they do it.
As you can see in the image below, adapted from Muybridge's Animal Locomotion, the gaits have been broken down into symbols illustrating which leg strikes the ground in which order, assuming the animal is facing north with the right legs on the right and the left legs on the left.
For example, with the rotary gallop gait, if you start your cycle with the left rear foot striking the ground first, the next in sequence to hit the ground would be the right rear foot, then the right fore foot, followed by the left fore foot.
As for the transverse and rotary gallops, I've found the rotary gallop more often in reference material than the transverse, which I've mainly seen in horse footage. The canter is the roughest gait, with a lot of up-and-down movement. Elephants don't seem to follow these rules, and should be considered separately.
image adapted from: Animal Locomotion, Eadweard Muybridge, 1887
To save time, you could animate a "vanilla" gait cycle for each gait with the leg movements blocked in on keys and breakdowns only and the body and head having the rough up-and-down motion laid in on those keys. If using a universal rig, this file could then be exported onto any beast (with minimal adjustments, depending on the disparities of beast shape) and be used as a starting point for the animations.
Several different types or speeds of walks could also be created from this base file simply by playing with the amount of frames in the animation and the distance between the legs in the stride position or the distance the beast travels in the 'leap' part of the gallop.
The WalkIn the case of the walk gait, the rear left foot strikes first, followed by the left foreleg. The rear right leg strikes third, with the right foreleg falling last. The walk is the slowest gait, and is shared by all quadrupeds. Muybridge breaks down this information into a chart for the walk, trot, canter and gallop gaits in the introduction of Animal Locomotion. Converted into a graphic table, a walk cycle would look like this:
image adapted from: Animal Locomotion, Eadweard Muybridge, 1887
Image adapted from Horse Locomotion Walk 01, courtesy of www.rhinohouse.com (Click for larger image)
Adapted from Preston Blair, Animation, 1948
Animating A WalkTo illustrate this locomotion in 3D animation, I've roughed in a slow 40-frame walk cycle. Cycles must be symmetrical, or there will be a visible hitch in the walk, like a limp, or a hit in the animation.
Details like toes and tails can be ignored or turned off at this stage. I create the four major keys or poses of the walk: two stride and two passing. I make them as symmetrical as possible, but they don't have to be mathematically the same.
There is an advantage to keying all major elements on the same frame. At this point, the keys can be slid around easily to change the timing of the walk. It is quick and easy to adapt and manipulate your cycle by figuring out your basic timing to the point where you start to add finishing details like overlap and follow-through. Keys arranged in an orderly fashion are really easy to manipulate in your 3D software package (here I am using the dope sheet in Maya 2011).
Four key poses, JoJo walk, property of Rocket 5 Studios (Click for larger image)
JoJo walk cycle, four keys only, with smooth spline interpolation. Watch the animation by clicking here.
JoJo with wonky arm movement. Watch the animation by clicking here.
Grab spline handles and move them so that curve looks like it can cycle or repeat. (Click for larger image)
JoJo walk from side view, tail and toes added. Watch the animation by clicking here.
Walks and Runs: In BriefWalks and runs can be considered a controlled fall with a little acceleration happening right after the passing position, which is similar to a push-off. As with all movement cycles, the forward or Z-translation would be non-linear.
The speed of the walk is dictated by the length of the legs and how far apart the feet are planted in the stride position. There isn't really a moment where all four legs are off the ground, as in the other gaits, and the legs can only move so fast without looking "sped up". Conversely, the speed of gallop is largely determined by the shape and unique qualities of the beast. The faster you need the beast to go, the more flexible the spine will have to be, and the greater the squash and stretch. Look for this when watching reference. As the legs bunch up under the beast (the squash) energy is gathered, preparing for a "leap" or "stretch" where the animal can cover as much ground as its form, weight and strength allow. The tighter the squash, the more extended the stretch and the faster the beast can travel.
Personality, the key ingredient in any good animation, comes not only from the shape of the key poses but also from what is happening in between the poses. How the character gets from stride to passing can define the character. Are they high-stepping? Straight forward and no-nonsense? Whimsical? Are they flopping around like a puppy or are they hard and densely muscled like a pit bull? The overlapping elements that you've added to the animation and their follow-through shows the audience who the character is and what it is made of.