Toggle Culling Back/Front

This removes the faces of volume elements for all elements or for the surface of the structure, depending on the state of ''Toggle Surfaces/Volumes''. With this option, the user can visualize internal structures like cracks or a core of a hollow structure.
For shell elements, the behavior is different. Initially only the front faces are illuminated and the back faces are dark. This is helpful to determine the orientation of the elements. If you want to see all faces of the shell-elements illuminated regardless of the orientation, then use this option. If you want to change the orientation use the command ''qflp''.