CSS2DRenderer: Just traverse visible object (#28330)

* add cache empty check and set a default value

* Update CSS2DRenderer.js

* Update CSS2DRenderer.js

Fix code style.

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Co-authored-by: Michael Herzog <[email protected]>

examples/jsm/renderers/CSS2DRenderer.js

@@ -124,6 +124,7 @@ class CSS2DRenderer {
 				hideObject( object.children[ i ] );
 
 			}
+
 		}
 
 		function renderObject( object, scene, camera ) {
@@ -186,7 +187,7 @@ class CSS2DRenderer {
 
 			const result = [];
 
-			scene.traverse( function ( object ) {
+			scene.traverseVisible( function ( object ) {
 
 				if ( object.isCSS2DObject ) result.push( object );