I have two questions concerning the Tracking Tools API 2.1:
1.) Is there a possibility to determine which marker of a currently tracked rigid body is visible for the system with the help of the Tracking Tools API (NPTrackingTools.dll)? TT_TrackableMarker(int RigidIndex, int MarkerIndex, float *x, float *y, float *z) returns the 3d position of all markers completely defining the rigid body system. But how can I detect, whether the specified marker is really seen by the system or whether it is invisible (because of occlusions) in the current frame?
2.) In which way can I influence the pivot point of a defined rigid body system? TT_CreateTrackable(...) only sets the marker positions. The rotation of the rigid body system is relative to the position of the pivot point, so it is important for me to be able to define this position explicitly.