Rotoscoping running - How?

Rasheed · Post by **Rasheed** » Sat Sep 23, 2006 8:45 pm

Here's what Richard Williams wrote about rotoscoping (The Animator's Survival Kit, page 106):

Richard Williams wrote:WE DON'T GET WEIGHT BY A SMOOTH LEVEL MOVEMENT.

When we trace off a live action walk (the fancy word is rotoscoping), it doesn't work very well. Obviously, it works in the live action - but when you trace it accurately, it floats. Nobody really knows why. So we increase the ups and the downs - accentuate or exaggerate the ups and downs - and it works.

I guess the same applies to running, although in this case the stick figure is rather convincing. Anyway, why would I doubt the great Richard Williams? And, of course, it is exactly what jahnocli wrote earlier in this thread and Vern suggested.

So the consensus seems to be that rotoscoping is fine, but you have to give it some extra attention, to make it "believable". It's no use copying in animation what you can shoot in video, but it is a good starting point, especially for noting the changes in perspective. However, you can (and should) go beyond that.

So, in essence, the timing of life action and animation is roughly the same, but the spacing is quite different. The timing in this case seems to be easy:

1/3rd of the running cycle, one foot touches the floor
the time between one foot leaving the floor and the other foot touching it, is 1/6th of the running cycle; in that period of time, the body is free from the floor and follows an arc, much like a bouncing ball does (deceleration towards the top of the arc and acceleration towards the bottom of the arc)

Here's an observation about the spacing that both the life action and the animation have to obey:

the speed of the body in horizontal direction is constant if and when the running speed is constant

The running body is travelling at a constant rate. This means that once the foot touches the floor, the body has to travel at that exact same speed, relative to the foot on the floor. The one part that reflects the speed and direction of the body best is the center of the hips. That has to travel at a constant speed and the leg that is propelling the body at that moment has to support that speed and direction.

The only substantial change in speed is in the vertical direction, when the body is free from the floor. That is where you can make a difference as an animator, giving more expression to the running action. And, of course, in the secondary animation (arms, chest, head, clothing and hairdo). Although I think there is a possibility for additional animation when a foot is in contact with the floor, not in horizontal direction (because the horizontal speed is constant), but certainly in vertical direction.

I'm sure there are a lot of other things to consider and maybe some of my observations are incorrect. We will see...

heyvern · Post by **heyvern** » Sat Sep 23, 2006 11:15 pm

My problem was that I couldn't... quite... remember what a sexy walk looked like (haven't been on a date in ages)...

... so... I was walking around my house swinging my hips and I got very self concious about what the neighbors might think if they saw me.

-vern

jahnocli · Post by **jahnocli** » Sun Sep 24, 2006 10:47 am

heyvern wrote:My problem was that I couldn't... quite... remember what a sexy walk looked like (haven't been on a date in ages)...

... so... I was walking around my house swinging my hips and I got very self concious about what the neighbors might think if they saw me.

-vern

Ha ha ha! I would have paid to watch that!

Rasheed · Post by **Rasheed** » Mon Sep 25, 2006 10:46 pm

Well, I'm way beyond that stage and couldn't care less what the neighbors think about the way I move my body. Have you ever seen someone with spasms? Now that is something that's scary to see, those wild movements, especially when you're in a shop or at the mall and don't expect something like that. And most people couldn't care less. I, OTOH, thought the whole situation was quite amusing, but that's just my strange look at the world of seeing humor in someone's (or my own) mishap in life.

Now about using video to create animation. I have seen some video clips at http://www.tartan.nl and decided that you should use video only as a reference, but not as a source. I guess the best way is to take your sketchbook to the track or a running event, and use it to note your observations in an artistic way. Once you have a good idea for an animation, you could use rotoscoping for getting the technical part right.