IK handle makes joint rotate

#1

Hello! I’m a newbie in rigging, and i’m making my first arm rig. I already made both the FK and the IK joints, and everything seemed to be
fine until I attached my meshes to make some tests:

When I use my custom attribute to switch between IK and FK, my elbow rotates by 90
degrees. I tought it probably has something to do with my PoleVector,
but I really don’t know how i could fix this problem.

Here’s an attached gif of the issue: the only thing i’m doing is changing my
IK_FK_Blend custom attribute (It works by balacing weights between the
orient constraint of the two chains on the final joint) between 0 and
1.
How can I fix this? Thanks in advance for the answers :slight_smile:

Here’s a link to the GIF

#2

Hi,
Just the work flow for IK/FK
Create the joint at shoulder , elbow and wrist.
Orient the joint with X axis pointing the child joint.
Few things to keep in mind:
 All the joins should be in same plane to avoid flip
 Create an ikRP Solver to check if the joint get rotation. Better to avoid rotation transforms.
Duplicate the joint after applying IK, to have your FK and Skin joint chain
Do your switching through IK/FK attribute connected to the constraints of the Skin joint, which is constrainted to the IK?FK chain.
Placing the poleVector control:
Create a linear curve from shoulder to elbow then wrist.
 Grab the cv on the elbow, Set the move tool axis “orientation” to “Normal”, pull the cv to a distance in “N” direction.
 Snap the poleVector control on the cv and apply poleVector constraint to the ikHandle to get non flipping IK?FK switch
Regards,