Each clipping plane can be moved a specified distance from its current position, where distance is a real number in the current display units (usually angstroms). A positive number moves the plane towards the user, while a negative number moves it away from the user. The plane may be hither or yon.
Clip moves the clipping plane in the specified manner for the specified number of image update frames (default 1). ~Clip will halt an ongoing clip. These parameters are useful for controlling the rate of clipping and are helpful when constructing command scripts and making videos. Commands continue to be processed while the requested motion is in progress. To pause command processing until the motion is finished, use the wait command.