Answered

Inaccurate conversion from FK to IK

Sean W 2 weeks ago updated 1 week ago 2

I'm trying to convert some clips from FK to IK, but there's some inaccuracies! I followed the instructions in the UMotion Manual under "Clip Editor > FK to IK Conversion > Improving Conversion Accuracy." Unfortunately the steps didn't seem to help much! I included a video of me trying the steps and showing the results.

Any other tips on how to get a more accurate conversion?


fk to ik inaccuracte conversion

UMotion Version:
1.20p04
Unity Version:
2019.1.0f2

Answer

Answer
Answered

Hi Sean,
thank you very much for your support request.

The FK to IK conversion is "lossy" by it's nature (because IK has less degrees of freedom than FK). By comparing the before/after pose from your video it looks like the algorithm is only off by a few degrees (at least that's how it looks on the video to me, let me know if I've overseen something). Assuming that you convert your animation to IK because you want to modify it anyways, this small imperfection are usually acceptable.


If you need to further improve the animation, add a duplicated version of your character to Unity Timeline with the original animation attached. Then use the "Sync" button to synchronize UMotion with Unity Timeline. That way you can preview both animations at the same time (overlaying each other, toggle visibility of the Timeline assigned character) so you can manually do some adjustments where needed.

Please let me know in case you have any further questions.

Best regards,
Peter

GOOD, I'M SATISFIED
Satisfaction mark by Sean W 1 week ago
Answer
Answered

Hi Sean,
thank you very much for your support request.

The FK to IK conversion is "lossy" by it's nature (because IK has less degrees of freedom than FK). By comparing the before/after pose from your video it looks like the algorithm is only off by a few degrees (at least that's how it looks on the video to me, let me know if I've overseen something). Assuming that you convert your animation to IK because you want to modify it anyways, this small imperfection are usually acceptable.


If you need to further improve the animation, add a duplicated version of your character to Unity Timeline with the original animation attached. Then use the "Sync" button to synchronize UMotion with Unity Timeline. That way you can preview both animations at the same time (overlaying each other, toggle visibility of the Timeline assigned character) so you can manually do some adjustments where needed.

Please let me know in case you have any further questions.

Best regards,
Peter

Thanks for the recommendation, I'll be sure to try that out!