      Instructions on using the LGD mouse interface on the IRIS


The control panel shows which 'mode' you're in.  To change modes, press
a key.  The modes and their keys are:

	Key				Mode
	---				----

	'r'				rotate
	'z'				zoom
	't'				translate
	's'				scale
	'f'				field of view
	'w'				twist

	'h'				halt
	ESC				reset

When in any of the first 6 modes, you effect the relevant operation by
moving the mouse while holding down the left or middle mouse button.
The left button does absolute motion --- the rate at which the view
changes is proportional to the speed of the mouse.  The middle button
does relative motion --- it accelerates the rate of change by an
amount proportional to the speed of the mouse.  (This effect is much
harder to control than absolute motion, but can be fun.)  When you
release either mouse button, the motion continues with the most recent
mouse displacement vector.  To stop the motion, hold the mouse still
and press and release the left button, which has the effect of setting
the displacement vector to 0.

Each mode has its own displacement vector which is retained upon
switching modes.  Only the displacement vector of the current mode is
affected by mouse motions.  Thus, for example, if you begin a rotation
by releasing the left button while moving the mouse in rotate mode,
and then switch to another mode, the rotation will continue
independently of the new mode.

To zero all displacement vectors, bringing everything to a halt, enter
halt mode (press the 'h' key).  The mouse does nothing when in this mode.
Switch to another mode to start moving again.

To reset the picture to a factory-determined default view, enter reset
mode (press the ESC key).  The mouse does nothing when in this mode.
Switch to another mode to start moving again.

The sliders in the control panel control the depth cueing parameters.

To save the current values of these parameters in a file, press the
'>' key.  A box will appear in the panel; move the cursor to a point
INSIDE this box and type a file name, ending with the <return> key.
To read the values of the depth cueing parameters from a file which
has been written in this way, press the '<' key and enter a file name
in the same way.
