Editor: Avoid scale NaNs. See #4946.

editor/js/Sidebar.Object3D.js

@@ -79,9 +79,9 @@ Sidebar.Object3D = function ( editor ) {
 
 	var objectScaleRow = new UI.Panel();
 	var objectScaleLock = new UI.Checkbox().setPosition( 'absolute' ).setLeft( '75px' );
-	var objectScaleX = new UI.Number( 1 ).setWidth( '50px' ).onChange( updateScaleX );
-	var objectScaleY = new UI.Number( 1 ).setWidth( '50px' ).onChange( updateScaleY );
-	var objectScaleZ = new UI.Number( 1 ).setWidth( '50px' ).onChange( updateScaleZ );
+	var objectScaleX = new UI.Number( 1 ).setRange( 0.01, Infinity ).setWidth( '50px' ).onChange( updateScaleX );
+	var objectScaleY = new UI.Number( 1 ).setRange( 0.01, Infinity ).setWidth( '50px' ).onChange( updateScaleY );
+	var objectScaleZ = new UI.Number( 1 ).setRange( 0.01, Infinity ).setWidth( '50px' ).onChange( updateScaleZ );
 
 	objectScaleRow.add( new UI.Text( 'Scale' ).setWidth( '90px' ) );
 	objectScaleRow.add( objectScaleLock );