Pixel size to Layer3D size (for BS Contact)

gistfile1.js

function initialize() {
	refresh();
	Browser.addRoute(Browser, 'windowSize', Browser.getScript(), 'refresh');

	distance = viewpoint.position[2];
	fieldOfView = viewpoint.fieldOfView;
}

function shutdown() {
	Browser.deleteRoute(Browser, 'windowSize', Browser.getScript(), 'refresh');
}

function refresh(){
	var vrmlSize;
	var screenSize = Browser.windowSize;
	if (screenSize[0] > screenSize[1]){
		vrmlSize = new SFVec2f(
			Math.tan((Math.atan((screenSize[0] * Math.tan(fieldOfView / 2)) / screenSize[1]) * 2) / 2) * distance * 2,
			Math.tan(fieldOfView / 2) * distance * 2
		);
	} else {
		vrmlSize = new SFVec2f(
			Math.tan(fieldOfView / 2) * distance * 2,
			Math.tan((Math.atan((Math.tan(fieldOfView / 2) * screenSize[1]) / screenSize[0]) * 2) / 2) * distance * 2
		);
	}


	var x1 = 0.5 * vrmlSize[0];
	var y2 = -0.5 * vrmlSize[1];
	var y1 = y2 + (vrmlSize[1] * 256 / screenSize[1]);

	// [Other] layer size: doesn't use the distance and fieldOfView
	background.size[1] = 256 / screenSize[1];

	// IFS size: uses the distance and fieldOfView
	coords.point = new MFVec3f(
		new SFVec3f(-x1, y2, 0),
		new SFVec3f(-x1, y1, 0),
		new SFVec3f(x1, y1, 0),
		new SFVec3f(x1, y2, 0)
	);
	trace(coords.point);
}