1 if vrworld object is valid, 0 if not
x = isvalid(vrworld_object)
A vrworld object is considered valid if its associated virtual world still exists.
x = isvalid(vrworld_object) returns an array that contains a 1 when the elements of vrworld_object are valid vrworld objects, and returns a 0 when they are not.
You use this method to check whether the vrworld object is still valid. Using a delete or vrclear command can make a vrworld object invalid.