View Full Version : Help With Bones!

The Great Raja
02-09-2003, 04:33 PM
I am looking for an online tutorial or the like (Or even a LW Guru that knows bones) to help me.

I am trying to set up bones in a human character, and nothing works right. Most of the tutorials I have found are for 5.6

When ever I pick up the foot, the knee twists almost 90 degree inward.

02-09-2003, 05:51 PM
Ok the attatchment doesn't want to work, try this:
It is very stable and a snap to setup. There's only one IK target per limb so it updates pretty fast too.

Use the heading on Knee Pointer to point the knees; don't touch any of the other red bones. The green bones are not part of the red bones hierarchy, and do not use IK. Use Heel to move the foot/leg and to rotate the foot on its heel; the bone itself does not affect any points in the object. Toes will rotate the foot on its ball and the toe points are assigned to it via a weight map. Foot rotates to raise the heel while keeping the toes planted; it has the remainder of the foot points assigned to it, and the IK target for the leg is the child of this bone. You don't need to touch IK Target.

If you need the foot to rotate at the heel, give Heel a parent bone with its pivot point at the heel; in that case you don't use the heel to move the leg, you would use the ankle-rotator bone to move the foot; it also would have no points assigned to it.

Two other things to watch out for: First of all, your object should be to scale; no people that are 2 kilometers tall or 1 micron tall. The other thing to do is pre-bend the joints so the IK solver knows which way the limb should bend.

The Great Raja
02-09-2003, 06:24 PM
Thanks, what is happening is that when ever I lift the foot at the heel the leg twists at the knee 90 towards the other leg.

I'll try what you' got and see how it goes

Thanks again

BTW could this be a lack of weightmaps problems. EI not having a Weightmap for each bone?

02-09-2003, 08:13 PM
Weight maps wouldn't cause a problem like that. It's probably that the IK isn't assigned to the appropriate channels or the scale is off.

BTW, to add to my previous post, I've noticed that with short, stubby-legged characters the above IK setup needs a little tweaking to keep the knees from being wobbly; On the Knee Pointer, set the bank to IK and turn off the "unaffected by IK of descendents" option. On the thigh, set the heading and bank to keyframes instead of IK. You may need to record the bones pivot rotations and then record their rest position to get it to rotate properly.

The Great Raja
02-09-2003, 08:46 PM
Thanks, I'm new to bones and stuff. Not to LW, just bones.

IS there a way to reset the rotation of both nulls and bones so that they are aligned? (Other than by hand) and Does this even need to be done?

The Great Raja
02-10-2003, 02:23 AM
When constructing Skelegons in modeller. Should the Handles always face either down (Like for a foot) or in the -Z axis (Like the spine)
What about the Hands/Fingers, Where should the handle face?

02-10-2003, 04:38 AM
The bank handle AND the skelegon form a plane. The pitch of the skelegon will reside in that plane.
When you adjust the bank handle on a skelegon its really adjusting the pitch for the child and so on.
The bank handles are created perpendicular to the viewport you draw them in.
Weight maps in no way effect bone orientation or IK settings.
All they do is bias vertices more towards specific bones.

02-10-2003, 12:52 PM
Originally posted by The Great Raja
IS there a way to reset the rotation of both nulls and bones so that they are aligned? (Other than by hand) and Does this even need to be done?

I'm not quite sure what you mean here. You can record the pivot rotations if you want, but it isn't always necessary. What that does is keep an items current orientation but sets the HPB values to 0,0,0 so it's kind of like switching it to local coordinates. If you do this on a bone you should record the rest position afterwards or you will end up with some pretty wild deformations.

08-21-2003, 11:35 AM
Hi there,

Go over to 3d-palace, register and download the huge LW rigging video tutorial and you shall be enlightened.

Best Wishes