Invisible

Makes the object invisible (or dimmed) when the signal is high.
The signal is usually connected to a digital signal, but can also be connected to a string.
In this case the object is invisible when the string is empty. Invisible can also be used with
the xtt-command 'check' to, for example, check if a method is defined for an object. In
Attribute you then write $cmd('command'), for example

      $cmd(check method/method=Note/object=VK-Valve)

Attribute		Description
Invisible.Attribute		Signal in the database of type Boolean that should
		influence the object.
Invisible.Dimmed		1 dims the object, 0 makes the object invisible.
Invisible.DimLevel		A transparency value between 0 and 1 to add
		transparency to the dimmed appearance.
Invisible.Instances		Instance mask where instances can be added or removed.