Inverse Kinematics controlling 3 bones.


So from the Picture you might see what I’m trying to accomplish. I want the Bone above the yellow bone to bend in the direction of where the red arrow is pointing, Just like the yellow bone is bending in the direction of the Green arrow. How Do I do this? I’ve attached the blend file, Thanks in advance! http://resources.guild-hosting.net/20140904911/themes/core/images/smileys/grin.gif

Attachments

My problema.blend (478 KB)

Hi,

you have to rotate it a bit in bind pose already, and it will follow this direction when effected by the IK solver.

I’ve done that, but it still turns out like the above.

I only know one good way to do this. It involves another control to deal with but is mostly automated. It’s a separate IK control for the extra leg bone and works like a pole target (but with greater influence on bone location).

My problema 2.blend (482 KB)

Best to just examine the file but here’s what I did (bone names underlined) :

Set the chain length on Lower bone’s IK constraint to 2.

Moved Pole target back close to High bone’s tail. This is going to be High bone’s IK target.

Put a Copy Location constraint on Pole target back targeting IK Bone. Settings are X Y and Z location toggled on. Y Inverted. Offset on. Local Space. Low influence. You can adjust influence and set Y loc inverted or not as you prefer (inverted Y seemed to work better with foot raised really high).

Btw Pole target back is not parented to anything. In a finished armature this and any other bone not parented to anything else would be normally be parented to a “Root” bone.

Put an IK constraint on High bone. Its target is High bone target. Chain Length 1.

I parented Pole target Front to IK bone so it moves with IK bone rotation. Some prefer it be parented to the armature’s root bone. Which way is best depends on specific needs and preference.

Welcome to Blenderartists.org

-LP

The simplest way to do this is to forget the second pole target and adjust the stiffness of each bone in the chain (IK panel, bone properties tab) so they start bending all together and in the desired direction, which is decided by pre-bending the joints a little in edit mode.

Thanks a bunch! This will help me greatly! http://resources.guild-hosting.net/20140906912/themes/core/images/smileys/grin.gif