Help with pathfinding ai

Help and Feedback Scripting Support
#1

Hello, I’m trying to make a pathfinding ai script, but I keep getting an error.

--// ... \\--
local character = script.Parent
local hrp = character.HumanoidRootPart
local humanoid = character.Humanoid

--// Services \\--
local PathFindingService = game:GetService("PathfindingService")
local RunService = game:GetService("RunService")


--// Functions \\--

local function GetNearestPlayer(position)
	local nearestplayer = nil
	local nearestdistance = math.huge
	for i,v in pairs(game.Players:GetPlayers()) do
		if v.Character then
			if v.Character:FindFirstChild("HumanoidRootPart") then
				local position = (v.Character.HumanoidRootPart.Position - position).Magnitude
				if position < nearestdistance then
					nearestplayer = v
				end
			end
		end
	end
	if nearestplayer == nil then return end
	return nearestplayer.Character.HumanoidRootPart
end

function GenerateRandomDestination()
	local hrp = character.PrimaryPart or character:FindFirstChild("HumanoidRootPart");
	local randomPos = hrp.Position + Vector3.new(math.random(-50, 50), 0, math.random(-50, 50));

	return randomPos;
end

function GoToNearestPlayer()
	local target = GetNearestPlayer(hrp.Position)
	local path = PathFindingService:CreatePath()
	path:ComputeAsync(target.Position, hrp.Position)
	
	for _,waypoint in pairs(path:GetWaypoints()) do
		humanoid:MoveTo(waypoint.Position)
		
		if waypoint.Action == Enum.PathWaypointAction.Jump then
			humanoid.Jump = true
		end
		humanoid.MoveToFinished:Wait()
	end
end

RunService.Heartbeat:Connect(function()
	GoToNearestPlayer()
end)

The error:

Argument 2 missing or nil  -  Server - AI:43
17:18:46.311  Stack Begin  -  Studio
17:18:46.311  Script 'Workspace.Shop.AI', Line 43 - function GoToNearestPlayer  -  Studio - AI:43
17:18:46.311  Script 'Workspace.Shop.AI', Line 56  -  Studio - AI:56
17:18:46.311  Stack End  -  Studio
1 Like
#2

This might help since it is an api doc Humanoid | Roblox Creator Documentation

#3

I’m not asking for docs, I know what Humanoid:MoveTo does. I’m asking for help with the error.

#4

yes and the error is specifically saying that a second parameter is missing, although I am confused on what parameter that happens to be since I haven’t had to add more than one parameter at a time.

#5

I changed some stuff up:

--// ... \\--
local character = script.Parent
local hrp = character.HumanoidRootPart
local humanoid = character.Humanoid

--// Services \\--
local PathFindingService = game:GetService("PathfindingService")
local RunService = game:GetService("RunService")


--// Functions \\--
function GetNearestPlayer()
	local test = game.Workspace:GetChildren()

	local max_dist = 50
	local target = nil
	local test_hrp
	for _,v in pairs(test) do
		if v:IsA("Model") and game.Players:FindFirstChild(v.Name) then

			test_hrp = v:FindFirstChild("HumanoidRootPart")

			if (hrp.Position - test_hrp.Position).magnitude < max_dist then
				target = test_hrp
			end
		end
	end
	if target == nil then return end
	return target
end

function GenerateRandomDestination()
	local hrp = character.PrimaryPart or character:FindFirstChild("HumanoidRootPart");
	local randomPos = hrp.Position + Vector3.new(math.random(-50, 50), 0, math.random(-50, 50));

	return randomPos;
end

function GoToNearestPlayer()
	local target = GetNearestPlayer()
	local path = PathFindingService:CreatePath()
	path:ComputeAsync(target.Position, hrp.Position)
	
	for _,waypoint in pairs(path:GetWaypoints()) do
		humanoid:MoveTo(waypoint.Position)
		
		if waypoint.Action == Enum.PathWaypointAction.Jump then
			humanoid.Jump = true
		end
		humanoid.MoveToFinished:Wait()
	end
end

--RunService.Heartbeat:Connect(function()
	GoToNearestPlayer()
--end)

Error:

Workspace.Shop.AI:45: attempt to index nil with 'Position'  -  Server - AI:45
  19:05:39.585  Stack Begin  -  Studio
  19:05:39.585  Script 'Workspace.Shop.AI', Line 45 - function GoToNearestPlayer  -  Studio - AI:45
  19:05:39.585  Script 'Workspace.Shop.AI', Line 58  -  Studio - AI:58
  19:05:39.585  Stack End  -  Studio
#6

I’m fairly sure the issue here is that sometimes the AI isn’t able to generate a path which means that an error will always occur. I suggest adding a check to see if the AI is blocked; or if the path failed to generate.

#7

How could I do that?
characters

#8

Its always best to put anything that has a chance of failing into a pcall

#9

I’m pretty sure the error is coming from the GetNearestPlayer function. “target” is nil. “attempt to index nil with ‘Position’”. I need to figure out how to make target not nil.

function GetNearestPlayer()
	local test = game.Workspace:GetChildren()

	local max_dist = 50
	local target = nil
	local test_hrp
	for _,v in pairs(test) do
		if v:IsA("Model") and game.Players:FindFirstChild(v.Name) then

			test_hrp = v:FindFirstChild("HumanoidRootPart")

			if (hrp.Position - test_hrp.Position).magnitude < max_dist then
				target = test_hrp
			end
		end
	end
	if target == nil then return end
	return target
end
#10

In that case define the target variable outside of that function since every time it runs it gets redefined as nil.

#11

Simply put, your not checking if the waypoint.Position is nil. At least that’s what it seems.

#12

Well we wont know what target is until there’s a player within 50 studs.

#13

It’s something to do with target being nil.

#14

But if it gets redefined everytime then that could just cause problems, as I am suspecting

#15

Then how do I prevent it from being a problem?

#16

define it outside of the scope

#17

I’m confused.

We won’t know what target is until there’s a player within 50 studs. Could you provide code or explain more?

#18 
local target

function a()
  target = plrname
end)
#19

Try the above. It was edited…

#20

Use ipairs to iterate over waypoints