Very Computer

I've never really done any character animation yet, only space scenes,
logos, and other stuff (I'm farmiliar with bones, IK, and most of the
character animation theory), and I've been postponing the facing with
this problem for quite a time...

v5.5, IK. The test scene is simple, a cylinder (15 segments), and 3
bones in it. One main bone and 2 child bones. A null is a goal object
to the last child bone in a chain, the limits are set, we can start
to animate. I move the null object, the bones follow it, but the motion
is so jerky and not smooth I just can't believe it's happening. In 20
frames of moving from A to B the are at least 5-6 "shocks"...

I know you know... :) So any help will be appreciated...

I've never really done any character animation yet, only space scenes,
logos, and other stuff (I'm farmiliar with bones, IK, and most of the
character animation theory), and I've been postponing the facing with
this problem for quite a time...

v5.5, IK. The test scene is simple, a cylinder (15 segments), and 3
bones in it. One main bone and 2 child bones. A null is a goal object
to the last child bone in a chain, the limits are set, we can start
to animate. I move the null object, the bones follow it, but the motion
is so jerky and not smooth I just can't believe it's happening. In 20
frames of moving from A to B the are at least 5-6 "shocks"...

I know you know... :) So any help will be appreciated...

It sounds as though the three bones are probably all deforming bones. It
is usefull to create a null bone at the end of the chain to target the
IK goal. It is the base of a bone that points, so if the bone doing the
pointing has a long rest length you can will get obvious sudden changes
in rotation.

If this is not the problem, then keep in mind that IK can tend to jump
around if the goal object is at any real distance from the IK pointer.
Try to keep the pointer in contact with the goal. This is not always
necessary but can help.

Hope this helps

Adrian

Quote:

> > I've never really done any character animation yet, only space scenes,
> > logos, and other stuff (I'm farmiliar with bones, IK, and most of the
> > character animation theory), and I've been postponing the facing with
> > this problem for quite a time...

> > v5.5, IK. The test scene is simple, a cylinder (15 segments), and 3
> > bones in it. One main bone and 2 child bones. A null is a goal object
> > to the last child bone in a chain, the limits are set, we can start
> > to animate. I move the null object, the bones follow it, but the motion
> > is so jerky and not smooth I just can't believe it's happening. In 20
> > frames of moving from A to B the are at least 5-6 "shocks"...

> > I know you know... :) So any help will be appreciated...

> In my best experience, Lightwave IK don't work too well.

Marko,

I have a web page with fairly extensive info on IK at.

http://ourworld.compuserve.com/homepages/crestline/ik.htm

It will probably take a little practice to work the kinks out of
your IK scheme. One thing you might try just to get things
rolling is to enable only _one_ axis of rotation for each bone in
the Mouse panel (you know the H,P,B settings). These effect
the behavior of IK on top of the IK Limits. So turning off the
axes you don't want may begin to give a little greater control
to start.

-Tim Wilson, Crestline