In addition to aligning separate clouds to each other a lower level adjustment can be made to align separate scan passes. To do so, right-click on the cloud of interest and select Refit Scan Passes. This will build a new, adjusted point cloud aligned to the specified tolerance. The alignment transform and statistics are recorded within the new cloud’s History.
Each time a scan is started and stopped a new scan pass is recorded. These passes can then be aligned to each other using the features measured within the scan and adjusting the relative transforms of subsequent scans passes to the first.
This can be helpful in two ways. In cases where an instrument made a significant shift in position, such as shifting to the far side of a part but is still measuring into the same point cloud, this tool can help align the passes to each other. This could correct for a slight instrument calibration error in a particular joint for example. This is very helpful in smoothing a resulting mesh.
Second, if you combine two or more point clouds into a single cloud using a construction command these scans will be marked as separate passes within the resulting cloud. The re-fit scan passes can then be used to refine the alignment of these separate cloud passes within the cloud with respect to each other.