SYNOPSIS
  mixed P_VMaster

DESCRIPTION
  This property is used when implementing virtual objects.
  Its value is the master object (or its file_name()) of a group of virtual
  objects.

  If the gamedriver tries to load an object whose file does not exist,
  it first asks the object causing the load resp. this objects environment
  to supply an object which is to be used in place of the nonexisting one.
  It does this by calling the lfun compile_object(string filename) in
  the objects, passing the requested filename as argument.
  If the loading object resp. its room have the P_VMaster property set,
  the compile_object() lfun is not called in the objects themselves, but
  in the returned VMaster object instead.

  If one of the compile_object() returns a valid object, this returned
  object is given the requested filename as if it has been compiled from
  that file.

  Virtual objects are useful to implement largish areals in which most
  rooms have common features. The exits between the room may be written
  as if the room really exist in separ
  ate files, while in fact only those
  rooms with special features really exist as own file. All other rooms
  are generated on demand according to the creational rules of that areal.

  The P_VMaster property allows to separate the virtual room objects from
  the master controlling all the virtual rooms.

EXAMPLE

AVAILABILITY
  Include: <b/base.h>
  Availability: /b/base and descendants.

  Applys to every object, queried by /secure/master.

SEE ALSO
  base(b), virtual(basics)
