ABSTRACT
This chapter discusses placements of markers on props for optical systems, and the same principles that work with human capture subjects. When one of the markers is occluded by the performer there will be only one marker to be tracked. If an occlusion happens for a short period of time, one may be able to fill in the gap by applying a spline interpolation. When both of the markers are occluded for a period of time and reappear, the application that reconstructs trajectories may swap them in the middle of the sequence by mislabeling them. Marker swapping can happen when a stick is quickly rotated as well. If the motion capture software does not give skeletal or rotational data, the marker data is brought into the three-dimensional application, and a spline curve is created using the marker positions as the positions of the control vertices (or end points) of the curve.
