It’s mostly meaningless there. However, it’s fairly close to what you need, and arc-tracking tools should be a regular part of your polishing kit. You also want to bring in the concepts of overlap and follow-through, by not having the same spacing for different parts of the character. Remember the concepts of acceleration, velocity, translation? This can mean tracking a dozen different parts of the character to get it right. If you want a character to appear massive, you need to give it more frames to slow down and speed up as it moves. Is Your Demo Reel Ready for a Major Studio? Another common spacing error is to have spacing changes when there is no force acting on the character. Slow in and slow out really just describes a specific spacing solution* to stopping or starting movement in a naturalistic way. Get ready for some physics! You have entered an incorrect email address! Spacing (along with arcs) defines how that action happens. Finally, good spacing isn’t the same as super smooth spacing. That said, sometimes this jitteriness seemed to be a feature—Ray Harryhausen’s wonderful skeletons in Jason and the Argonauts—but usually this gritty, jerky movement was a bug. Here are three spacing charts that all show a slow out from the key pose at frame 1 and a slow in to the key pose at frame 17. In sum, the relationship between forces and acceleration is axiomatic. Velocity: the rate of change of position over time (speed with directional information) Slow ins and slow outs are just the tip of an iceberg. We’re covering the 12 Basic Principles of Animation one principle at a time, and we’re only halfway done! Slow In and Slow Out: The 12 Basic Principles of Animation, Follow-through and Overlapping Action: The 12 Basic Principles of Animation, Arc: The 12 Basic Principles of Animation, 3D Shot Breakdown: Cartoony Animation with Torben Soettrup, Dos and Don’ts For Developing Your Character Animation Reel, Why Maya 3D Animation Courses Are Essential For Beginners, Why All Animators Need to Master the Moving Hold. CTRL + SPACE for auto-complete. Get more information about Animation Mentor’s Character Animation Courses. When you are cleaning up your spacing, you are not grooming your curves. 1. Decreasing spacing is negative acceleration, or deceleration. Spacing goes from large to nil over one frame. You don’t want waste that time if your timing and posing are still changing. 3. This will show both the arc of the movement, and the spacing of that part of the character. For a given force, a more massive object will accelerate more slowly, which we know means the spacing must increase more gradually. Start your animation journey by learning with professional animators from a variety of studios and career paths! That’s more drawings or more frames in the slow out. Animation Mentor is the original online animation school. When the spacing is constant, there is zero acceleration, and the velocity is steady (as in a typical walk or run). This is another common mistake—having objects slow in as they’re about to hit the ground. Every part of a moving character is going to follow its own arcs, and have its own spacing. They start together and finish together. In the same way, in the vast majority of cases, objects accelerate or decelerate in a logical fashion, and all those accelerations and decelerations together make up the nature and rhythm of the movement. Conversely, the gradual reduction in speed when coming to a stop, again portrayed by extra drawings, became known as slow in. You can see lots of spacing errors in early stop-motion animation, where animators worked straight ahead and had no way of monitoring their spacing. ‘Slow In’- an action decelerates into a key frame meaning that the object will move slower. The third illustrates a very gradual slow out, and a very rapid slow in. On a basic level, Slow In and Slow Out describes the tendency of things to come to rest, or to start moving, in a progressive way. An abrupt stop with a bounce and settle, as when something is dropped to the ground, and then briefly bounces back in the opposite direction, before settling. Position is where we’ve posed our character. The electric car will have a smooth and rapid acceleration to it’s top speed, and then it will have even spacing. Today we’re taking it slooooooooooow. Well, not so fast. This became known as a slow out, because the extra drawings slowed the action down at the beginning of the movement, just like in real life.Conversely, the gradual reduction in speed when coming to a stop, again portrayed by extra drawings, became known as slow … It’s true that if you change your timing, you will change your spacing, but they aren’t the same thing. In the second, the slow out is a bit slower than the slow in. Many of us who learned this trick continue to use dry erase markers right on the screen. By varying the number of in-betweens, the nature of the slow in or slow out is made more gradual or more rapid. Also, cleaning up spacing can be fussy work. This became known as a slow out, because the extra drawings slowed the action down at the beginning of the movement, just like in real life. We can broaden this principle to consider spacing more generally. This is a principle that most people understand pretty quickly, as it’s easy to observe in life. An abrupt stop with an overshoot and recoil, as when a character sticks a landing with their feet, but the body overshoots and snaps back (great for cartoony work and really sharp movement). Put simply, acceleration is in the spacing. We have some useful spacing tools for CG animation. The conventional car will accelerate more slowly, and have brief decelerations each time the driver shifts gears, but it will still be accelerating at the finish line, with a higher top speed. In the early days of hand-drawn animation, even spacing was commonly used (which gives the same effect as linear tangents in Maya). The most common spacing mistake is having spacing that increases and decreases erratically, often from frame to frame. © 2014 - 2019 Next Education LLC. Realize that, while Maya spline tangents of whatever flavor give us very definite slow ins and slow outs, they are also computerized, generic guesses at the right acceleration/deceleration. How many times have you had someone suggest you “work on your arcs and spacing”? Here are some quick simplified physics definitions: Position: where something is in space The more gradual the spacing changes, the gentler the acceleration, and vice versa. And when that object comes back to rest, the spacing progressively decreases to zero. You need to define the spacing of the movement in your animation, based on your character’s physiology, personality, and the style of animation. No slow out, no slow in, and equal movement between every drawing. The movement was abrupt, then smooth, and mechanically unnatural. Both velocity and acceleration bring time into the mix. An abrupt stop, as when something lands on the ground and immediately settles in the final pose. The massive object can go as fast as the lighter object, but it won’t accelerate as quickly. In the traditional animation days, we often tracked arcs and spacing on a separate sheet of animation paper, using various colored pencils for different body parts. This is especially true when working with IK controls. Save my name, email, and website in this browser for the next time I comment. It’s that simple. The biggest weakness of arc tracking tools is that they usually track a control curve, or a joint, instead of the relevant part of a character’s geometry. Imagine an electric car and a regular car in a quarter-mile race. ‘Slow Out’- an action accelerates out of a key frame meaning that the object moves faster. 2. How often have we seen a character run and jump, and after they’re airborne they speed up (spacing increases)? Trust me, this will be useful. That’s the key concept here, so ponder it until it’s clear. Spacing should be progressively increasing or decreasing in a meaningful way in each section of the overall movement. Big spacing changes between drawings means large movements. Acceleration describes how velocity is changing over time. Don’t make the mistake of “fixing” the spacing graph editor curves. Find out why you need to know about it, what it looks like, and how to use it to improve your own animation. Same timing but very different spacing. A path of action is a series of meaningful arcs. Think of a 300-pound lineman and a 90-pound gymnast in a sprint running over an obstacle course. Of course, we almost always have the force of gravity pulling things down, and that’s why when a character is falling, the downward spacing increases until the character hits the ground. Sometimes you want some grittiness in the movement, like Harryhausen’s skeletons.