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Hello Blender community,

I recorded a simple animation with a Rokoko motion tracking suit, for a character. It consists in a walk from a point A to a point B. In between the character zigzag a bit, but nothing complex.

I exported the recorded rig as an .fbx with a Mixamo rig and imported it in Blender. There, it shows up and works fine.

Only that, because of the scene's composition the character/rig has to start at a different location and at a different angle (Z-axis) than the recorded and ultimately exported motions. To make it more understandable, let's say the rig was facing North when we recorded motion, but ultimately, the character has to face South in the scene.

Normaly there would be a couple of way to deal with this. The most straightforward consisting in moving the rig at the appropriate location and angle and the trick is done.

Although, Rokoko does seem to record differently from what I understood, so that each bones location is keyframed at every frame. Hence, moving the rig itself doesn't work, as it would require to keyframe every frame of the animation.

There is also no 'main bone' to constrain to a location or angle.

Second solution I thought of really confused me. I was pretty convinced NLA should do to the trick: to push the original animation as an action and to add another action where the rig is placed at the desired location and angle. Then, Blending the two with 'combine'.

Except that it only half works. The starting location is correct using NLA, but the animation doesn't quite take in consideration the new angle. So that when the animation plays (with the two blended NLA actions), the rig follows the same path as in the original animation, only that the rig is inverted to 180°, so that basically it now walks backward.

To some extent there is part of my head that get the logic and why it doesn't work, without being able to rationaly explain it. Although, the question remains: is there a way one can alter the location and angle of an already recorded animation with Rokoko setup?

Here is a link to download a test blend file that show the 'backward' issue: Rokoko_test.blend

Thank you for any tip or hint!

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  • $\begingroup$ i think the number of people who have a rokoko is very low...but if you provide your blend file, we can check it out and search for a solution $\endgroup$
    – Chris
    Feb 15, 2022 at 19:44
  • $\begingroup$ Indeed, this is rather expensive device and their customer service isn't the quickest I must say. It isn't mine and I am just operating it for someone else, hence tip-toing on these issues. I added a link with a file in the original message. $\endgroup$
    – Bertrand
    Feb 15, 2022 at 21:57

1 Answer 1

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The procedure is a bit tricky, because there is an error on the data transfer between Mocap and rig: all the animation which should have been assigned to the spine bone (which acts as root of the rig) has been assigned to the whole rig object instead.

To solve you have to transfer thoose data form the rig object to the hip bone (spine).

One way to accomplish:

Delete all NLA data and open an action editor with mocap animation applied to the rig.

On frame 1 go to pose mode select the spine bone, Shift S > cursor to selected. Back to object mode create an empty and set copy loc and copy rot constraint targeting the spine bone.

Object menu > Animation > Bake action (all options turned on, only empty selected).

In the action editor delete all animation data which are applied to the rig object and to the spine bone.

In edit mode set both LeftUpLeg and RightUpLeg bones child of the spine bone.

In pose mode add to the spine bone a copy loc and copy rot BONE constraint to the spine bone, targeting the empty, then Pose menu > Animation > Bake action (All options tuned on, having only spine bone selected).

Delete the Empty.

With this procedure you will end up with an animated rig that you can freely move and rotate in object mode.

enter image description here

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  • $\begingroup$ Hello Josh, Thank you, that solve the issue! So this is what I gathered, location data aren't properly exported from Rokoko to blender, as a 'mixamo' rig + .fbx. I tried out different exporting options this morning, and had recommend to export as a .bhv using a mixamo rig. With this format, data aren't enforced on each bone, so one can manipulate the rig at their convenience. Other rigs, such as Maya's one didn't work for me, despite Rokoko's staff recommending that option. $\endgroup$
    – Bertrand
    Feb 16, 2022 at 14:53

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