Animation Retargeting Issues

I’m new when it comes to animating/rigging/skinning in Blender, so please excuse my ignorance here, as I am coming from a 3ds Max Biped background.

I have a BVH Mocap file which I cleaned up inside Blender, but I want to retarget that animation to a skinned model (humanoid).

From all methods using the Rokoko Addon worked the best, and I had to copy the imported BVH Rig and adjust it to my humanoid mesh (bone placement) for skinning.
This makes it so that the bone structure and naming is 100% the same, the only difference being that some bones are slightly shorter or at a different rotation (feet slightly outward instead of straight forward).

Source RIG

Target RIG

Bone structure

When retargeting the animation i’d say about 80% of the animation get’s transfered correctly, but there are a couple of big issues.

Mainly the fingers and hands are in different positions and have completely inaccurate rotations almost compared to the original animation.
Even the feet are not pointing straight forward, I tried editing the bones in the feet to see if it changes the outcome in the animation but it did not.

This is how the hands + fingers is supposed to look like

This is how the retargeted animation looks like in the hands + Fingers
Rotations are off aswell as they have different positions warping the hands/knuckles

Here are the original feet rotations

Here are the retargeted feet

At the moment I am completely stuck and have no idea how to fix it, and I do not want to fix this by manually in the animation itself.
Blender workflow regarding character animations is completely new to me…

If anyone can point out to what I am doing wrong or missing or point me in the right direction, that would be great!

FYI;
It my imported bvh has a different scale (it’s still 1.1.1) but is bigger in size than my target RIG.
If I make my source RIG the same size and apply the scale, than the retargeted animation becomes “floaty”. I don’t know if this info is important or not, hence why I put it in here.

EDIT;
Here are some better screens regarding the hands


Source

When copying bone rotations from the source to the target, the same thing happens, so i’m guessing that it’s not hte rokoko addon that’s not working but rather something on my part with the target RIG i think.

Changed the “roll” setting on the bones in the fingers slighly, on the RIG version where I used Copy Bone rotation instead of retarteting the animation.
Seems to have fixed some issues.


Doing this same method on the RIG that doesn’t have Copy Bone Rotation and just has the animation retargeted, yields not good results.

I have also experienced this issue using the Rokoko retargeting.

Here is my character in a pose before retargeting:
Skærmbillede 2021-12-16 144139

Here is the character in the same pose after retargeting a seperate animation onto the character:
Skærmbillede 2021-12-16 144241

For some reason the legs are rotated inwards. This is not a one case scenario or issue. I experience this every time I retarget an animation onto my character.

I am retargeting from a character imported into Mixamo, animated, downloaded and imported into Blender. Then retargeting the animation onto the original character’s skeleton (as Mixamo has altered the original skeleton). So bone names are the same in the bone list. Just for clarification.

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Yeah for future MoCap work I think i’m going to stick it with 3ds max and use their Biped system (much easier) and than probably export to Blender to do the clean up.