Zones

When creating an online virtual world its often helpful to think of that world much like that of the Earth, as a collection of geographical regions connected together by arbitrary boundaries. Each particular region may have a different size but in a game its typical to associate each of these regions with a single map as defined in the game engine. We call these regions Zones in the Virtual World System. Therefore, a Zone is synonymous with a single game engine map or region of your virtual world.

Linking Zones

Zones define a particular region or space within the virtual world. They can connect to other zones by aligning the boundaries of two zones together on a particular side or boundary line. The system is a coordinate-agnostic system, meaning that it defines no rules with regards to how you define your world coordinate system. If you prefer to build each map using global coordinates or prefer localized coordinates the system will function the same.

The only thing the system cares about is the relationship between zones. When you define a zone within the Virtual World System you define all zones that share a physical boundary with it, referencing only the unique id of the adjacent zone. This allows for the creation of virtual worlds of any complexity, whether that be zones which lay side-by-side one another or stack in three-dimensional space. The choice is yours.

Population Limits

Each Zone definition has a maxShardUsers and autoCreateShards property that can be used to control the creation of shards and the number of players that are able to connect to each server instance.

The maxShardUsers property is used to determine the population capacity for the zone when deciding how to scale the number of shard instances according to the defined Scaling Policies. Therefore, if you define 100 users as the maximum number of users per shard, then each game server shard instance will allowed up to 100 users to join it. Once the shard has reached maximum capacity, no additional players will be allowed to join. The system will also add an additional shard when the total population capacity reaches a particular threshold as defined by the scaling policy in order to increase the total number of users the system can handle automatically.

Limiting User Access

It is also possible to limit access to a particular zone by defining a list of allowed user id’s and role names. The allowed property takes a list of all the user identifiers and role names that are have permission to join the zone. When specifying the user id, users must match the authenticated universally unique identifier of the user attempting to join the zone. When specifying a role name, the authenticated user trying to join the zone must be a member of the defined role.

This may be useful to gate access to particular zones based on their product subscription level, or purchase history, or by their participation in a beta program. This may be also useful to isolate zones to particular teams or groups of players during development.

Zone Metadata

It is possible to describe any metadata you desire in a Zone definition. However, there are a few metadata properties that are important when it comes to deployment and scaling of the game servers that will ultimately serve players in your virtual world. Each property described below is considered optional and will not impact the performance of the system if they are omitted from the Zone definition.

buildVersions

The buildVersions metadata property allows you to define a Zone that only works for particular build versions of you game or application. This may be useful when developing zones that are specific to a particular version of the product such as a content patch or a version 2.0. This may also be desirable to create specific virtual world topologies during testing or prototyping where you don’t want to expose a particular zone to other developers or branches.

Example:

{
    "data": {
        "buildVersions": [
            "1.0.0",
            "1.1.0"
        ]
    }
}

initOptions

The initOptions metadata property is used to specify initialization options or parameters that will be sent to the game server instance when a shard is assigned for the given zone. This is useful to identify which map to load, what gameplay mode to use or other gameplay options specific to your zone. It is defined as a list of arguments that will be sent to the server. The server is then responsible for interpreting the list accordingly.

Example:

{
    "data": {
        "initOptions": [
            "MyMapName",
            "gameMode=Dungeon"
        ]
    }
}

regions

The regions metadata property is used to limit the datacenter regions that a Zone shard will be launched within. This can be useful when testing new zones for a particular regional audience or for providing region-specific content in order to comply with local government regulations. The system will only launch shards in the regions listed. If no regions are listed, the default behavior is to launch at least one shard in every available region.