View Full Version : Offsetting keyed joints

 tron_thomas04 April 2006, 04:37 AMI found this link while I was researching walk cycles on the Internet: http://www.anticz.com/Walks.htm In the article, the author makes a comment I found confusing, and I was hoping people in this forum could explain it. The author says, "I like to go through and off set keys on overlapping joints to loosen up everything and give it a more natural feel." As far as I know each joint is separate and independent from all other joints. Joints do not overlap, intersect, or touch each other. What does he mean by overlapping joints? Another thing I can't tell from the statement is this. What if there were two overlapping joints were key framed at frame 12. To offset them, one joint could offset to be keyed at frame 11 and the other key framed at frame 13. However it could also be that one offset to be keyed frame 10, and another at frame 14. How big are these offset typically?
musashidan
04 April 2006, 04:57 PM
Overlapping or breaking of joints means if for instance you have an arm swinging then shoulder joint moving will cause the the bicep to drive the forearm which will drive the hand and in turn the fingers.So obviously they don't all move at the same time so when the action has been blocked out on the sme frame you would go into the dopesheet and offset keys so that the upperarm moves ahead of the forearm moves ahead of the hand and so on.......
This limbers up the motion and applies to everything:the head,legs,hips,etc...
It is often refered to as successive breaking of joints.

tron_thomas
04 April 2006, 01:41 AM
Okay, I think I understand the concept.

What metrics are useful for determining how far apart joint key frames should be offset?

I would suspect this would depend on the frame rate of the animation. Also, it seems that the offset would probably be pretty small as there usually isn't a lot of latency in one body part reacting to another.

stewartjones
04 April 2006, 07:29 AM
Okay, I think I understand the concept.

What metrics are useful for determining how far apart joint key frames should be offset?

I would suspect this would depend on the frame rate of the animation. Also, it seems that the offset would probably be pretty small as there usually isn't a lot of latency in one body part reacting to another.

Metrics!?!? I always thought that animation was creative, and not that technical. Go with your gut, see what looks good, and you will have your answer. :)

musashidan
04 April 2006, 09:24 PM
Metrics!?!? I always thought that animation was creative, and not that technical. Go with your gut, see what looks good, and you will have your answer. :)

Exactly,animation is hugely reliant on the animator "feeling" when something is right.don't get too bogged down on technical issues.Yes,there are rules or principles of animation but once you understand them they are there to be bent or even broken.Offsets are generally only a frame or 2 for most things as the motion is only subtley changed but enough to give the effect of more fluid,natural motion.
if you can get your hands on a camcorder then taping yourself or your friends is a good source of reference.

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04 April 2006, 09:24 PM
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