NavMesh

The NavMesh table reads the game's navigation mesh: the walkable surface the game's AI uses to find paths on foot. Use it to check whether a point is reachable on foot, to snap positions to walkable ground (for spawn points, NPC destinations or checkpoints), or to visualize the walkable area.

Available on: Client

The navmesh is streamed: only the 3 x 3 tiles of 512 m around the camera are loaded at any time (about 1.5 km x 1.5 km). Everything outside that area is invisible to these functions, and results near the edge can change as the camera moves. For the road and sidewalk network of the whole map, see RoadGraph.

Functions

NavMesh.GetClosestPosition(position, maxDistance)

Finds the closest point on the loaded navmesh to position, searching at most maxDistance away.

Parameters

Name	Type	Description
position	vec3	World position to search from.
maxDistance	number	Search radius, in meters.

Returns vec3 (a point on the navmesh) or nil when there is no navmesh within maxDistance, or no navmesh loaded.

Example

-- is the point the player aims at walkable?
Cmd.Add("walkable", function()
	local target = World.LocalPlayer():AsPlayer():GetAimPosition()
	local on_mesh = NavMesh.GetClosestPosition(target, 1)

	print(on_mesh and "walkable" or "not walkable")
end)

NavMesh.GetVertices(position, radius)

Returns every vertex (polygon corner) of the loaded navmesh within radius of position. The distance is measured in 3D. Large radii in dense areas can return many thousands of points, so keep the radius small if you call this often.

Parameters

Name	Type	Description
position	vec3	Center of the search.
radius	number	Search radius, in meters.

Returns table: a list (1-based array) of vec3 positions, empty when none is found.

Example

-- draw the navmesh vertices around the camera
Event.Add("OnRender", function()
	for _, vertex in ipairs(NavMesh.GetVertices(Camera.GetPosition(), 30)) do
		Render.DrawSphere(vertex, 0.1, vec4(0, 0.6, 1, 1), false)
	end
end)

NavMesh.GetPolygons(position, radius)

Returns the navmesh polygons that have at least one corner within radius of position (measured in 3D). Each polygon is given as its corners in order around its edge, so consecutive corners (and the last and first) form its sides.

Parameters

Name	Type	Description
position	vec3	Center of the search.
radius	number	Search radius, in meters.

Returns table: a list of polygons, each a list of vec3 corners. Empty when none is found.

Example

-- count the walkable polygons around the player and their area
Cmd.Add("navinfo", function()
	local polygons = NavMesh.GetPolygons(World.LocalPlayer():GetPosition(), 20)
	local area = 0

	for _, corners in ipairs(polygons) do
		-- triangle fan from the first corner, area on the horizontal plane
		for i = 2, #corners - 1 do
			local a, b, c = corners[1], corners[i], corners[i + 1]
			area = area + math.abs((b.x - a.x) * (c.z - a.z) - (c.x - a.x) * (b.z - a.z)) / 2
		end
	end

	print(string.format("%d polygons, %.0f square meters", #polygons, area))
end)