The default ue4 skeleton animations are always off.
If you are using a free pack, chances are the animations are also off.
With that in mind:
- your finger weight paint is bad.
Because of where the finger is causing the bend.
That portion should be weight painted to the bone before so that the bend can only happen on the skin crease.
- this may also not matter, if the movement of the flange is overly overextended to the metacarpal.
All people are different, but without help, you can barely get an upward (against normal direction) bend of more than approx 5 degrees, if even.
So while the paint looks to be bad, maybe it doesn’t matter.
- initial bone rotations are what matters.
The way the pose “looks” may not reflect the bone position. this could be a modeling issue if you just threw the mesh around the skeleton without specifically placing bone heads and tails to the center point of the finger loop.
A mesh that’s just been thrown into an epic armature.
A (badly) corrected bone that is actually aligned with the position of the geometry. just that one bone. The rest would all need the same treatment.
(You should snap the bone and preserve the bone length, not do what I did which was stretch the bone altering it’s rotation. Still the image gives an example of the alignment - and a “what not to do”)
A decent way to fix things is to copy the bone rotations over from the mannequin to the base mesh you intend to retarget.
Going one bone at a time, that’s 10*3 plus 2 (one for each hand) X Y and Z rotations that you have to copy over.
Using blender, you can do this in POSE mode, and then apply the pose as the rest Pose to cause the mesh to acquire the new position as the base to which the engine or animations apply distortion.
Afraid not. It mostly looks like a model issue.
Editing the base is your fastest/permanent fix.