spring 1.0
----------

REQUIREMENTS: VMD Version 1.1 or greater, use in orthographic mode

DESCRIPTION:
	After an atom has been picked, call "spring".  It generates a
	a mechanical spring from the location of the atom outward toward
	the eye position. By default the spring has a radius of 3 A and
	a length of 20 Angstroms.  These and other parameters can be
	altered in well-labelled parts of the procedure if desired.  This
	script is useful to those who do simulated micromanipulation
	experiments.  It comes in handy when explaining the method by 
	which parts of the protein were pulled.


PROCEDURES:
	spring -  be sure to pick an atom before calling this

EXAMPLE OUTPUT
	Sample showing a spring added to an atom
	of the alanin molecule.  This image has been rotated by 90 degrees
	to make the spring fully visible.

DOWNLOAD THE FILE:
	spring.tcl

AUTHOR:
	Willy Wriggers (wriggers@ks.uiuc.edu)