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How to get world coordinates of a single marker?

by lpinilla » Thu Jun 15, 2017 12:47 pm

Hi,

I'm a student and for a project and for it the university allowed me to use the Motion Capture system.

For my project, I need to be able to record the world 3D coordinates of a single marker, I know that Motive captures RigidBodies which are any object with 3 or more markers but I was wondering if it could record only for one marker.

Thanks in advance.
lpinilla
 
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by steven.andrews » Fri Jun 16, 2017 8:19 am

Hello lpinilla,

It is possible for you to record the position of an individual marker, though this does require some more manual work. When recording the data, you will not be able to associate an asset to the marker for automatic tracking, since this will be a single marker that is not part of a known pattern.

When recording unlabeled markers, there are a number of factors, such as occlusion, that can cause the ID for the marker to suddenly change. To fix this, you will want to manually label the marker after recording. This will allow you to identify the marker throughout the Take, applying a consistent ID that you can recognize.
http://wiki.optitrack.com/index.php?title=Labeling#MarkerSets

Once labeled, you can export your marker data like normal to view its coordinates.


I hope this helps to get you going. If you require any further assistance with this, please feel free to reach out to us at help.naturalpoint.com

Best,
Steven
--
Steven Andrews
OptiTrack | Senior Customer Support Engineer
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by lpinilla » Fri Jun 16, 2017 12:10 pm

Thanks for the response.

Will this work even if I have multiple individual markers? because I want save the data of each individual markers. For example if I want to put a single marker to know the trajectory using mice, having a single marker on each one.

What I want to avoid is (following the example) to avoid the misinterpretation of the program of 2 individual markers and form a rigid body out of the 2 different test subjects (mice).
lpinilla
 
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Joined: Thu Jun 15, 2017 12:38 pm

by steven.andrews » Mon Jun 19, 2017 10:51 am

Hi lpinilla,

This process will work even if you are using multiple unlabeled markers. You will need to create multiple MarkerSets or multiple Labels within the MarkerSet. You can then label all of the markers and export their data.

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