Thickness changes the separation between the global clipping planes by the specified increment. The increment is a value in the current display units, usually Å; a positive number increases the distance between the clipping planes, whereas a negative number decreases it.
Thickness moves the clipping planes in the specified manner for the specified number of image update frames (default 1). 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. To halt an ongoing thickness motion, use freeze.
See also: clip, section, the Side View, clipping, movie-related commands