Relays TurnOn and TurnOff conditional on whether an object is currently on-screen. With the trap control flag Invert, it relays when the object is not shown. The object to test is specified with a ScriptParams link with the data set to Visible. If there is no link, then the script’s object is used.

A pseudo-script can send the message TestVisible and the script will reply with whether or not the object is visible. The first argument is either visible or invisible for which condition you want to check for.