ecmascript:

function roundoff (value, digits) // for local use only
{
	var resolution = 1;
	for (i = 1; i <= digits; i++ )
	{
		resolution *= 10;
	}
	return Math.round (value*resolution) / resolution; // round to resolution
}
function outputViewpoint ()
{
  var holdString = 
        '<Viewpoint position=\"' +
		roundoff (position.x, 1) + ' ' +
		roundoff (position.y, 1) + ' ' +
		roundoff (position.z, 1) +
        '\" orientation=\"' +
		roundoff (orientation.x, 3) + ' ' +
		roundoff (orientation.y, 3) + ' ' +
		roundoff (orientation.z, 3) + ' ' +
		roundoff (orientation.angle, 4) + '\"/>' ;
   tracePrint (holdString);
   outputViewpointString = new MFString (holdString);
}
function set_position (value)
{
	position = value; // save persistent value
	position_changed = position; // output event
	outputViewpoint ();
}
function set_orientation (value)
{
	orientation = value; // save persistent value
	orientation_changed = orientation; // output event
	outputViewpoint ();
}
function set_traceEnabled (value)
{
	traceEnabled = value;
	alwaysPrint ('traceEnabled=' + traceEnabled);
}
function alwaysPrint (text)
{
	Browser.println ('[ViewPositionOrientation] ' + text);
}
function tracePrint (text)
{
	if (traceEnabled) alwaysPrint (text);
}