Editing Basic Hits by Probing:

You can also update Basic hits by probing the part in Online mode or clicking on the CAD in Offline mode with the Measured Hits dialog box open. PC-DMIS automatically updates the dialog box with the new results.

For Basic hits, these check boxes appear:

Use Theoretical Vector As Approach Vector
This check box allows you to specify whether or not the theoretical vector should be used as the approach vector. If deselected, PC-DMIS calculates the approach vector by subtracting the theoretical hit point (X,Y,Z) from the current probe position.

Learn Hit During Execution
This check box allows you to specify whether or not PC-DMIS should relearn the basic hit during measurement routine execution.