View Full Version : bone displacement

09-15-2009, 08:36 AM
Is it possible to limit the bone displacement to the top end of a bone, like the knee of the shin bone?

09-15-2009, 04:10 PM
A weight map would be one way.

09-15-2009, 06:28 PM
How tedious. Is there not a gradient which recognizes the beginning or the end of a bone? And then maybe also one that recognizes the inside or the outside from that angle?

By the way SplineGod, I am new owner of PLK tools. So I see how Poser bones look. It's strange that Poser generally bends joints along the H axis and in LW you are supposed to set them up along the P axis. Although the H axis seems to work better dealing with gimbal lock.

09-15-2009, 07:35 PM
Well with zbones this is very easy. Just shorten the rest length.

09-15-2009, 07:53 PM
Scotts got a good suggestion/ Also try some of the new settings in the bone properties panel for displacements especially with joints.

Just z bones work with muscle flexing etc on the pitch. Joints are a bit more flexible.
I believe PLk has a script to import or convert bones to joints.
For gimbal lock you can always add an additional bone, use bone twist/record pivot rotation or set the mode to world coords and apply quaternian booster to that joint.

09-15-2009, 07:59 PM
Just shortening the rest length of the thigh bone has unpleasant effects on the thigh because the shin bone becomes dominant, Castius.

I am concerned with preserving the shape of the thigh and I hoped a bone displacement gradient would help. I used a support bone in the end. Disadvantage is that the support bone does not change its influence with the bend of the joint.

09-15-2009, 08:07 PM
You can also rotate, move, size that support bone as well.

09-15-2009, 08:17 PM
You mean driven by the angle of the bend with help of an expression?

09-15-2009, 08:39 PM
If you take away weighting in one area another HAS to replace it. Adding extra zBones as "hold" bones is the fastest way to achieve the weighting you are looking for. Because it give you new data to move around. that being the start and end position of the bones influence. Then you can simply control how much by adjusting it's strength.

For example. Say you want to have more gradient control over the thigh weighting.
1) Duplicate the thigh bone and rename to thigh_Def
2) Then parent it to the original thigh bone.
3) Set the original thigh bones strength to 0
4) now split the thigh_Def bone by 3

Now you have 3 thigh_Def bones you can control your weighting. The top middle and bottom bones. Sort of your own rough gradient control. Controlling where you split it will control how far up the shin can influence the thigh.

09-15-2009, 08:45 PM
Also remember you can set a bone strength above 100%

09-15-2009, 08:55 PM
You can also drive a morph using any bone channel.