Understanding how Shuffler works with layers
 
A map has to be seen as a sum of overlaying images that stack one on top of another as the user drops the Elements over the canvas. Of course upper Elements are fully visible, while lower ones are partially or fully invisible.

Elements that are below one or more other Elements cannot be selected and moved any more. By removing any Elements (or moving them a little bit) that are covering the lower Elements, or by using the switcher buttons to switch the whole upper layer on or off, you can then manipulate the lower Elements.

For this purpose, several Elements can be switched on or off thanks to special buttons placed into the upper left side of the GUI (Graphic User Interface).

Each button is provided with a red and green LED to remind you if its specific Elements are visible or invisible.

Layer buttons can be different for each application according to which Elements or effects are included, but they exist only for large number Elements or effects like: lights, dirt, fog, water.

Please keep in mind, that if you can see an Element that is located beneath a transparent part of another Element, you cannot directly select it without moving or turning the upper Element off.