CSS3DRenderer: Simplified fov calculation.

examples/js/renderers/CSS3DRenderer.js

@@ -261,7 +261,7 @@ THREE.CSS3DRenderer = function () {
 
 	this.render = function ( scene, camera ) {
 
-		var fov = 0.5 / Math.tan( THREE.Math.degToRad( camera.getEffectiveFOV() * 0.5 ) ) * _height;
+		var fov = camera.projectionMatrix.elements[ 5 ] * _heightHalf;
 
 		if ( cache.camera.fov !== fov ) {