Retargeting a Base Pose
There may be instances where you want to retarget animations to a Skeleton that is not quite using the same base pose as your Source Skeleton.
Take for example the Skeleton in the image below on the right.
Our Source Skeleton on the left is in a A-Pose while our Target Skeleton is using an T-Pose. Even though a Rig has been set up for them to share, if we were to retarget animations as is now, we may encounter issues as seen below.
In the image above, an animation has been retargeted for our Target Skeleton; however his arms clip into his side because the base poses were not the same. Thankfully, you can also retarget the Base Pose of your Target Skeleton prior to retargeting animations to reduce or eliminate issues like this from occurring.
In your Target Skeleton, under Retarget Manager, there is an option called Manage Retarget Base Pose.
If you click the View Pose button, you will see the current Base Pose. You can adjust it by clicking on a Bone and using the Rotation (E) widget.
In the image above, the right arm has been adjusted while the left arm is using the default base pose (which we can adjust by using the rotation widget). Once you have adjusted the pose, you can click the Save Pose option to save the retargeted Base Pose. With similar Base Poses between Skeletons, you can now retarget an animation and when the Skeleton Select window appears, you will notice that your Target Skeleton is now using a retargeted Base Pose.
Retargeting the animation with the retargeted Base Pose, results in a better looking animation.