VR Stereo Camera -
VRModules				               VR Stereo Camera (6)


NAME
     VR Stereo Camera - generate camera transformation events given
	a "vr device event" field.  The stream of camera control commands
	will control two cameras, "camera1" and "camera2".  Setting
	up these cameras properly from within the geometry viewer is
	your responsiblity.

SUMMARY
     Name	   VR Stereo Camera

     Type	   mapper

     Inputs	   field float 1D 1-space uniform
		   (VR device event field)

     Outputs	   AVS Geometry


     Parameters	   _N_a_m_e		   _T_y_p_e		  _D_e_f_a_u_l_t	 _M_i_n	   _M_a_x
		   Focal Length	   float dial	  50		 1e-5	   1e5
		   Window Width	   float dial	  1		 .001	   1e3
		   Eye Seperation  float	  7.5		1.	   30.

		   Eye		   string	  <read only>
		   At		   string	  <read only>
		   Up		   string	  <read only>
		*  Camera	   string	  "%camera1"
		   Reset	   boolean	  off		 off	   on

	* - this parameter is not wired up and has NO effect.

DESCRIPTION

	The VR Stereo Camera module will take as input events from a
	VR event field and then generate camera transformation events for
	TWO cameras which correspond to left and right eye positions.  
	These events are passed to the Geometry Viewer via the AVS Geometry 
	data type.

INPUTS
     	field float 1D 1-space uniform - VR device event field.  A set
	of C-language macros is used internal to the code for this 
	module to encode the device event information into an AVS
	field.  This field is not readily processible (unfortunately)
	by "normal" AVS modules.  This is the case because both
	floating point and boolean values are encoded into the field data.


PARAMETERS

	Focal Length - sets the distance between the position of the
	viewer and the view reference point, or the "look-at" point.
	Normally, changing this value will have no visible effect unless
	the camera uses perspective projection (selectable from within
	the AVS Geometry Viewer).

	Window Width - sets the window half-width.  Increasing this
	value increases the Field of View of the camera.

	Eye Separation - the degrees of seperation between the eyes.  This
	value is the size of the angle formed by the eyes and the viewpoint.
	The viewpoint is a function of "eye" position, "look at" direction
	and the focal length.  In general, decreasing this value will
	decrease the amount of the "stereo effect."

	Reality Check parameters - these values are a reflection of the
	variables internal to this module, and are read-only.  They show
	the position of the viewer, the look-at point and the up vector.

	Camera Name - a string which names the camera which will be
	affected by the events produced in this module.  This has not
	been thoroughly tested.

	Reset - a boolean used to reset the eyepoint, etc., to startup
	defaults.  This is useful if you fly off into oblivion.

OUTPUT

	AVS Geometry - containing camera transformation commands.  Feed
	this to the geometry viewer.
	

EXAMPLE
	division ipu
	    |   |
	VR camera UI
              |
	VR Stereo Camera
              |
	Geoemtry Viewer

RELATED	MODULES
	VR camera UI, VR Transform Camera, VR Transform Object



VRModules					  Lawrence Berkeley Laboratory
