While Richard Williams breaks it down to think about it as though you’re animating two bipeds walking, I find it far trickier as the relationship of the four legs adds more complexity. Once you feel comfortable with walk cycles I’d suggest attempting a quadruped. Getting two strides right that repeat is a lot easier than going through and perfecting 10. If you have a character doing a simple walk, then then cycle with an offset or copy & paste your curves. The forward motion is constant and the distance a foot travels in a stride is also a constant.
In a vanilla walk, everything is mathematical. Perhaps more rotation on the hips or bringing the heel back for a slightly shorter stride will solve your problems. Before you go searching for a stretch to fix your pops, look into those controls first. Knee pops are caused by the distance between the hip and heel becoming too long, it causes the knee to lock into an outstretched position and pop back into place when the hip and heel come back into regular proportion. Done well, it’s fine and unnoticeable, but more often that not it’s easy to see elastic legs. One thing I notice more commonly in student walks are legs stretching to avoid knee pops. One simpler way is to switch to FK when the foot is off the ground, swing through like a pendulum to the contact position and then switch back to IK for the foot plant. You can easily perfect the arcs and spacing on the heel and then find your knee arcs are popping back and forward. One fiddly thing in 3D animation is getting nice arcs using IK.
It’s quite easy to add in breakdowns and before you know it you have your first pass ready for polish. It’s a methodological approach of getting your base right, then working down from there into the details. If doing a vanilla walk, start with the contact positions 12 frames apart, put the passing position half way in between those two poses and then the down and up poses in between the passing and contact positions. I tend to think the key to a walk is getting the 4 main poses right from the start. The Survival Kit has more information than I could ever write about, here are some extra tips from my experience: Any imperfections in the mechanics are easily felt. Our expectations of what correct motion looks like is so much higher than say, two aliens fighting on Mars as our familiarity is so much more ingrained. Learn walks of all kinds, ’cause walks are about the toughest thing to do right”.Ī walk is something we see hundreds of times a day, and do ourselves all the time I had two friends comment yesterday they were using pedometer apps and were hitting 10,000 steps for the day. In the Survival Kit, Richard quoted Ken Harris saying: Through my current position as an animation lead at Sony I oversee crowds animation and I noticed one thing straight away when we started building our library of cycles: even senior animators struggle with walks. Almost a quarter of the book is about walks.I thought it’s a good time to reflect back on the book, through my eyes as a working/professional animator rather than a student.
His impact is no doubt in every animated film on screen today. It’s a book that sits on my shelf, has helped guide my understanding of animation and I think you’d be hard pressed to find a working animator who hasn’t gleaned knowledge from it in their career. An amazing career and character, but the knowledge he passed down through his Animated Survival Kit is what impresses me most. I woke up this morning to the unfortunate news that Richard Williams has passed away. Tim Rudders Animation Blog – /animationmentor/