RoadGraph

The RoadGraph table reads the game's road graph: the network of roads, sea lanes, air routes, sidewalks and railways that the game's traffic follows (cars drive the land roads, civilians walk the pedestrian paths on the sidewalks). Use it to find roads near a point, to spawn vehicles or NPCs on roads and sidewalks, or to build routes.

Available on: Client

Unlike the navmesh, the road graph covers the whole map and is loaded all at once. While the game has no road graph loaded (during loading), the functions return empty lists and nil.

The graph is made of nodes (junctions and road ends) joined by edges (the roads between them). Each edge has a RoadGraphType. Along every edge the game also stores samples, points spaced along the road's curve, which follow the road more closely than the straight line between its two nodes.

Node and edge ids are integers starting at 0 (unlike Lua arrays). The lists these functions return are ordinary 1-based Lua arrays.

Functions

RoadGraph.GetSamples(position, radius, types?)

Returns the road samples within radius of position (measured in 3D) whose edge type matches types. The sample heights are stored with a 0.1 m precision.

Parameters

Name	Type	Description
position	vec3	Center of the search.
radius	number	Search radius, in meters.
types	RoadGraphType	optional, default RoadGraphType.Any. The edge types to include. Combine several with bit.bor or by adding them, for example bit.bor(RoadGraphType.Land, RoadGraphType.Railway) or RoadGraphType.Land + RoadGraphType.Railway.

Returns table: a list of samples, each a table:

Field	Type	Description
position	vec3	The point on the road.
edge	integer	Id of the edge the sample belongs to (see RoadGraph.GetEdge).
type	RoadGraphType	The edge's type.

Example

-- pick a random sidewalk point near the player
local function random_sidewalk_point(center)
	local samples = RoadGraph.GetSamples(center, 150, RoadGraphType.Pedestrian)

	if #samples == 0 then
		return nil
	end

	return samples[math.random(#samples)].position
end

Cmd.Add("sidewalk", function()
	local point = random_sidewalk_point(World.LocalPlayer():GetPosition())
	print(point and ("sidewalk at " .. tostring(point)) or "no sidewalk nearby")
end)

RoadGraph.GetNodes(position, radius)

Returns the nodes within radius of position (measured in 3D).

Parameters

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

Returns table: a list of nodes, each a table { id = integer, position = vec3 }. Empty when none is found.

Example

-- draw the junctions around the camera
Event.Add("OnRender", function()
	for _, node in ipairs(RoadGraph.GetNodes(Camera.GetPosition(), 200)) do
		Render.DrawSphere(node.position, 1, vec4(1, 1, 0, 0.8), false)
	end
end)

RoadGraph.GetNode(id)

Returns one node by id.

Parameters

Name	Type	Description
id	integer	Node id, from 0.

Returns table { position = vec3 }, or nil when the id does not exist.

Example

local node = RoadGraph.GetNode(0)

if node then
	print("first node at " .. tostring(node.position))
end

RoadGraph.GetEdge(id)

Returns one edge (road) by id.

Parameters

Name	Type	Description
id	integer	Edge id, from 0, for example the edge of a sample.

Returns table or nil when the id does not exist:

Field	Type	Description
nodeA	integer	Id of the node at one end.
nodeB	integer	Id of the node at the other end.
length	integer	The road's length as the game stores it (a whole number, presumably meters).
type	RoadGraphType	What the road is for.

Example

-- which road is the player standing next to, and where does it lead?
Cmd.Add("road", function()
	local samples = RoadGraph.GetSamples(World.LocalPlayer():GetPosition(), 20, RoadGraphType.Land)

	if #samples == 0 then
		print("no road within 20 m")
		return
	end

	local edge = RoadGraph.GetEdge(samples[1].edge)
	local a, b = RoadGraph.GetNode(edge.nodeA), RoadGraph.GetNode(edge.nodeB)

	print(string.format("road %d, length %d, from %s to %s", samples[1].edge, edge.length, tostring(a.position), tostring(b.position)))
end)