This page describes how to integrate Gameware Navigation into your Lua gameplay code. You will learn how to add a navigation world, and spawn bots.

We provide a set of Lua scripts to start integrating Navigation in your runtime. These scripts are located in core/gwnav/lua/runtime and will therefore be available in your project.

The main component to integrate is the navigation world (requires navworld.lua).

From this object you will be able to:

• load navdata
• render the navmesh in the editor viewport
• send visual debug information to the NavigationLab.

In your level initialization create a NavWorld object:

function MyGame:init()
    self.navworld = NavWorld(world, level)
end

With:

• world: the engine world object
• level: the engine level object that represents your scene

The navigation world must be updated each frame.

You can also set a camera to use for visual debugging. When you connect the Navigation Lab to the engine, its camera can then track the camera in the interactive engine.

function MyGame:update(dt)
    self.navworld:update(dt)
    self.navworld:visual_debug_camera(self.maincamera)
end

To add NavData to a world:

function MyGame:init()
    local nav_data = self.navworld:add_navdata("levels/empty")
end

To remove NavData from a world:

    self.navworld:remove_navdata(nav_data)

In order to render the navigation mesh in the viewport, call:

self.navworld:debug_draw(gui, line_object)

You will need to pass an initalised Gui and LineObject to this function. You will also need to have added some NavData to the world.

function MyGame:shutdown()
    self.navworld:shutdown()
end

• add and remove bots, obstacles, runtime tagvolumes and navgraph

To add a bot to a NavWorld:

local configuration = NavBotConfiguration()
-- You can change any parameters of the configuration:
configuration.height = 1.8
local navbot = self.navworld:init_bot_from_unit(unit, configuration)

• unit is the Unit you wish to be driven by Navigation.

To remove a bot from a NavWorld:

navbot:shutdown()

To create a Box Obstacle:

local box_obstacle = NavBoxObstacle(navworld, unit)
box_obstacle:add_to_world()
box_obstacle:remove_from_world() -- obstacles is not destroyed, just no longer present in world

navworld is the NavWorld you wish this obstacle to reside in. unit is the Unit you wish to associate a Box Obstacle with. It will be configured according to the following scriptdata:

• half_extent - This Vector3 represents the halfextents of the Box.
• offset - This Vector3 represents the local center of the Box.
• is_exclusive - Whether or not this Obstacle causes the NavMesh to be no longer traversable where it intersects.
• does_trigger_tag_volume - Controls whether or not the obstacle changes the NavMesh.
• rotation_mode - This string can be either free or yaw. Yaw indicates that the obstacle only rotates around it's local up axis. Free indicates it can rotate in three dimensions.
• layer_id - The layer that this box should use when punching holes in the NavMesh.
• smartobject_id - The id of the smartobject (if any) associated with this obstacle.

To create a Cylinder Obstacle:

local cylinder_obstacle = NavCylinderObstacle(navworld, unit)
cylinder_obstacle:add_to_world()
cylinder_obstacle:remove_from_world() -- obstacles is not destroyed, just no longer present in world

navworld is the NavWorld you wish this obstacle to reside in. unit is the Unit you wish to associate a Cylinder Obstacle with. It will be configured according to the following scriptdata:

• radius - This radius of the Cylinder.
• height - The height of the Cylinder.
• is_exclusive - Whether or not this Obstacle causes the NavMesh to be no longer traversable where it intersects.
• does_trigger_tag_volume - Controls whether or not the obstacle changes the NavMesh.
• layer_id - The layer that this box should use when punching holes in the NavMesh.
• smartobject_id - The id of the smartobject (if any) associated with this obstacle.

To destroy an Obstacle:

box_obstacle:shutdown()
cylinder_obstacle:shutdown()