This bit indicates whether the PointData field specifies relative or absolute locations.
If set, each element in PointData specifies a location in the coordinate space that is relative to the
location specified by the previous element in the array. In the case of the first element in PointData,
a previous location at coordinates (0,0) is assumed.
If clear, PointData specifies absolute locations according to the #isCompressed() flag.
Note If this flag is set, the #isCompressed() flag (above) is undefined and MUST be ignored.