To see the properties of the virtual destination, double-click it or use the "Properties" command from the context menu. The following "Properties" window will appear:

properties_virtual

In the "Properties" window, the preview plays the incoming video for the current virtual destination in real time.

choose source button

Press the "Choose source…​" button to select other physical source for the current virtual destination. The "RTP sources" dialog box appears:

RTP_sources

Select the desired physical source you wish to add and press "OK".

set blank

Press the "Set blank" button in the "Properties" dialog to disable routing for the current virtual destination.