It is recommended to read the official documents carefully to understand the principle of IK Rig redirection. It is very helpful to understand how UE5 performs animation bone redirection and how to adjust the bones after redirection.
IK Rig Redirection
main function points
I Rig
The role of IK Rig is to define the bone chain of the main parts of the source bone and the target bone in the two conversion relationships. The chain
mainly defines the starting point-end point, IK tracking point (if any), and it does not matter if the number of bones in the two chains is not equal, IK Can automatically calculate the interpolation of the intermediate bone points.
The main components include:
and ten fingers.
IK Retargeter
The role of IK Retargeter is to map the skeleton chain of the main components of the source and target.
Mapping association of the left arm bone chain between source and target
If you get IKG assets from some cases, there may be a lot of associated bone chains in the case. After actual testing, redundant associations will cause problems. Even if there are parts with two corresponding bones, the association is correct. Distortion of bones can also occur.
Both the source and target bones have a clavicle bone, if the source and target clavicles are mapped and associated
The bones converted according to the IKG asset associated with the clavicle may have problems in the shoulder
The reason is that although the source and target bones both have clavicles, the organization of the two clavicles is different. If they are forcibly associated, there will be a problem of clavicle offset. If it is not associated, the IK reaction force bone algorithm can automatically calculate the arm-spine bone of the target through the arm-spine relationship of the source, which is more in line with the dynamics of the target bone. Makes bones more natural.
After removing the bones associated with the clavicle, the shoulder position is more in line with the dynamics.
The complete association is as follows (remove redundant associations):
the transferred bones will be more perfect
