After all the markers are properly labelled to segments, you can build Rigid bodies. This helps match markers and reconstruct gaps in data. Rigid bodies also extrapolate rotation data.

Before you add a Rigid body:

• A Rigid body can be built from as few as two markers, but it is recommended that you use three or more. Three or more markers let you acquire all rotation data from the Rigid body.
• When selecting markers for a Rigid body, look for markers that appear to be arranged in deliberate groups.
• A marker cannot be used in more than one Rigid body.

There are two methods for creating Rigid bodies: one method creates a Rigid body from a selection of markers, the second method lets you select each marker for the Rigid body as you go.