In TPP and GZ, the route system governs the behavior of AI agents such as soldiers. Routes are stored in route sets, defined in FRT files.

frt files can be opened and created with FoxKit. Further info here

Overview

A route is a linear sequence of nodes, each of which has a location in space. An agent acting along a route will travel from node to node, and upon reaching the end of the route, they will return to the first node and the route will repeat.

Although each agent only acts along one route at a time, multiple agents may patrol the same route together. In addition, an AI agent is assigned a number of routes, and which one they use at a given moment is dictated by the alert status:

• Sneak route: Used when the agent’s CP is unaware of the player.
• Caution route: Used when the encampment is on alert.
• Alert route: Used during combat alert. Combat AI usually uses a unique system, however, so having an alert route defined is rare.

You can change an agent’s sneak route in Lua by calling:

GameObject.SendCommand(gameObjectId, { id="SetSneakRoute", route=routeId })

where gameObjectId is the GameObject’s ID (obtained through calling GameObject.GetGameObjectId) and routeId is the name of the desired route, for instance, rts_ptr_e_citadel_W_0000. The caution and alert routes can be changed the same way, using “SetCautionRoute” and “SetAlertRoute” respectively.

Other uses

Routes aren’t only used for enemies. Helicopters also use routes, particularly for defining the approach and departure behavior for Pequod when using LZs.

Events

The most complex aspect of the route system are route events, and they are still not fully understood. There are two classes of route events:

• Node events are performed once an agent has arrived at a node.
• Edge events are performed while an agent is on their way to a node.

An example of a node event is CautionStandIdleReady, which causes the agent to stand idle in the caution stance. An example of an edge event is RelaxedWalk, which causes the agent to walk in a leisurely way to the node.

One of the most versatile node events is SendMessage, which can trigger a message in Lua, allowing you to write custom code to invoke whenever an agent arrives at that node.

As each event has different parameters, and not all of the event names have been discovered yet, this is still an area of active research. If interested, consider using FoxLib to unpack, edit, and create frt files to experiment with routes.

Notes

• Assigning a soldier to a nonexistent route will not crash the game, but seems to make the soldier disappear.

See also

• Routes
• Route descriptions