Get/Set the maximum number of worlds that can be created. The larger the number of worlds, the more memory that is initially allocated so care must be taken. Setting this value to one will reduce start-up memory usage to a minimum but will not allow any additional worlds to be created. The maximum value must be in the range of 1 to 1024. Any change will only be handled by Exiting Play mode in the Editor or restarting the player build. A single PhysicsWorld.defaultWorld is automatically created therefore occupies one of the available worlds.