Docs: Added conversion warning in geometry browser

docs/scenes/js/geometry.js

@@ -6,7 +6,13 @@ var twoPi = Math.PI * 2;
 
 function updateGroupGeometry( mesh, geometry ) {
 
-	if ( geometry.isGeometry ) geometry = new THREE.BufferGeometry().fromGeometry( geometry );
+	if ( geometry.isGeometry ) {
+
+		geometry = new THREE.BufferGeometry().fromGeometry( geometry );
+
+		console.warn( 'THREE.GeometryBrowser: Converted Geometry to BufferGeometry.' );
+
+	}
 
 	mesh.children[ 0 ].geometry.dispose();
 	mesh.children[ 1 ].geometry.dispose();