Marker clusters in Opensim

[Tom Augenstein]

Is there a way to incorporate marker clusters (rather than individual markers) into a marker set i.e. define a cluster object or class?

[jimmy d]

There is no class at the moment. What would you envision the methods on cluster class be?

[Tom Augenstein]

I'm not too sure what the methods of a class like that would be, maybe features like getRoll(), getPitch(), getYaw(), etc. or just commands that take advantage of the unique properties that a defined cluster offers over individual markers. Also, a sort of cluster structure library of OpenSim-provided or user-defined configurations that could be referenced and positioned/oriented could be more convenient for the user, both during data collection and post-processing in OpenSim. However, three individual markers (in theory) provides the same information that a cluster does, just in a less direct way, so I guess it doesn't make too much of a difference at the output.

I was more asking from the context of interfacing motion capture softwares with OpenSim. For example, I've found that working with clusters or any marker set established as a plane in Motive motion capture software is more convenient that working with individual markers. However, Motive only exports the marker cluster's centroid XYZ coordinates and not the XYZ of each marker comprising the cluster. This makes transition to OpenSim inconvenient/impossible if the tracking data was collected as clusters.