To set a live surface

The selected object becomes a live surface and its name displays beside the
Make Live icon
in the
Status Line. A live surface's wireframe color is dark green, but it only displays when
Wireframe or
Wireframe on Shaded mode is enabled.

To swap a live surface
) and select a previous live surface from the pop-up menu.
To quickly toggle the most recent live surface on and off
) or pop-up menu.