Hello @LuBuSniper. I didn’t want to leave you without an answer. I have a possible solution, but I don’t think we can use retargeting.
The main issue is that the bone hierarchy of both skeletons, specifically regarding the weapon bones, is very different. Even if we managed to fix the translations despite the hierarchy differences, we would likely have compatibility problems due to the initial rotations, and other animations might later generate strange rotations on the weapons.
I spent about two hours testing different types of IK setups and configurations. I even discussed it with a colleague at work, but the Weapon_r bone always ended up in the wrong place. And if Weapon_r seemed to be in the right position, the other bones, being relative to their parent, also ended up misaligned. The issue is that their positions should be absolute relative to the world. Tomorrow, if I have time, I’ll give it another couple of tries, but I’m not sure if it’s possible using Unreal’s retargeting system when the hierarchies are so different.
However, if what you need is to transfer the animation to your blue skeleton, I do have a simple solution that I know will work, but you would need to use another animation program such as Maya, Blender, or 3ds Max—whichever you feel most comfortable with.
What we can do is export the animation in our Target skeleton using retargeting, where it still uses the IK bones for the sword. Right now, it’s incorrect, but we’ll fix it.
Once we have the animation on the IK bones of our Target skeleton, and with our bones Weapon_r, T1, and T2 still without animation, we will take this FBX into our chosen animation software to edit the animation.
In your selected software, all we need to do is apply a Parent constraint without offset, using the following mapping:
- ik_hand_root → Weapon_r
- ik_hand_r → T1
- ik_hand_l → T2
In other words, Weapon_r should follow ik_hand_root.
With this setup, the new bones will always follow the IK bones without any issues, maintaining the correct positions and rotations exactly as in the Source skeleton’s animation.
Finally, the last step is to bake these three bones (Weapon_r, T1, T2), delete the constraints, export the animation, and re-import it into Unreal as an Animation Sequence for the blue skeleton.
I hope this explanation makes sense. If anything is unclear, let me know, and I’ll try to explain it again. But I believe this is the simplest and fastest solution.
Sorry that I couldn’t help much with the retargeting this time, but I hope I was able to solve the issue.
Best of luck with your project!
Best regards.