Hand / Finger Tracking

[MarShiim]

Hello everyone!
I'm a student from germany and new in this whole motive/tracking-thing. I'm curious about tracking hands and fingers with Motive. I want to do this live (not in edit-mode) and stream the data into Unity. I figured out, that the selectable predefined full-body skeletons only support markers attached to the forefinger, the little finger and the thumb.

So my question is: Is it somehow possible to have (or create) a skeleton consisting (maybe only) of a hand (maybe plus the arm), which supports tracking of all four fingers and the thumb? I fear that I cannnot manually create skeletons? I know that it is possible to manually label markers, but that won't work in live state, right?

If the skeleton-thing isn't possible, are there some workarounds how I can realize this? Maybe with a bunch of rigidbodies? If so, will it really takes three markers per rigidbody for each segment of the finger? (otherwise I cannot bend the finger because of the rigid in rigidbody.) That are a lot of markers really close to each other. I don't know how accurate this will be?

Many thanks!

[NaturalPoint-Dustin]

Hello,

Rigid Bodies would be your best option at this point. You will need to create 3 markers per rigid body. How many cameras and what camera model are you using?

Best Regards,

[MarShiim]

I use the Flex 13 system with twelve cameras.

[NaturalPoint-Dustin]

Thanks for responding. I would be happy to give more advice. But I will need more information on your system. Could I have you create a ticket with us at help.naturalpoint.com?

[MarShiim]

Yes, of course. Do you need all the data like hardware or license serialnumber?

[NaturalPoint-Dustin]

Thanks. I received the ticket.

[AnnaF]

Hi,

We currently have the same problem.
We would like to track the exact position of *all* fingers of the hand.
Is there support for automatic labeling and marker interpolation for the full hand (not only the index+thumb+pinky supported by the standard skeleton). Can I extend the standard skeleton somehow?

In the Wiki I saw the option of "Rigid Body Assisted Labeling". This seems to be well suitable for full hand tracking, as is also shown in the image in the Wiki. However, I could not find further instructions on how to do that.
Also would the Assisted Labeling also work with two hands close to each other?

Thanks a lot for your help!

[steven.andrews]

Hello AnnaF,

Unfortunately, our software does not currently support the ability to track each finger independently. It is possible to add a marker to each finger, or even more markers depending on your camera model and count, but this would have you recording unlabeled markers. You could edit the data, in post, to label the markers you wanted to track but this will be a lot of manual editing.
This process will not give you bone data for the fingers, only marker positions.

Rigid body assisted labeling is a useful feature that could help prevent swaps on the hands, but this will not expand the tracking to capture every finger as you might have hoped.
You can enable rigid body assisted labeling under the Advanced section in the Reconstruction Properties pane. If you need some more information on how this feature is expected to work, I encourage you to open a support ticket with us at help.naturalpoint.com so that I can better communicate with you.

I do not know how the system would behaving if rigid body assisted labeling was being used on each hand while the hands came together. Because of the nature of what this feature does, which is simply reconstruct the markers close to the rigid body with stricter settings, I do not foresee any issues. I am not sure, however, if this has ever been attempted.

Cheers,
Steven
--
Steven Andrews
OptiTrack | Customer Support Engineer

[TobiasM]

Essencially i'm facing the same problem. I want to track the detailed motion of each finger. Did anything change in the newest version of Motive:Body?
Currently we are running Motive 1.5 and are only able to stream and record unlabled marker positions with our Flex 13 System.

[steven.andrews]

Hello TobiasM,

Unfortunately, Motive 1.10 is still unable to capture the independent motion for each finger. Motive:Body does include a simple finger setup in which one marker is placed on the thumb, index and pinky. The rest of the finger motion is extrapolated from the three markers.

Unlabeled markers would still be the way to go if you are trying to place additional markers on the fingers. While Motive 1.10 does not contain any automated features to help with high resolution hand tracking, the labeling and editing tools have been improved and may be more useful for identifying the markers in Edit mode. Data quality has also been improved, and this may help to provide better hand data to work with.

Best,
Steven
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Steven Andrews
OptiTrack | Senior Customer Support Engineer