Pathfinding optimization

Help and Feedback Scripting Support
, , , ,
#1

Hello all

  1. What do you want to achieve?
    Fast and good pathfinding for enemies in my game

  2. What is the issue?
    I’ve implemented a pathfinding script for my enemies (following a bit of a tutorial) but It is quite slow and laggy and I don’t know how to go about it

(Keep in mind I’ve also searched on Developer Hub and though some answers could help I feel that this still will be a valid thread)

(pastebin code)

local PathfindingService = game:GetService("PathfindingService")
local enemies = game:GetService("ServerStorage").Enemies:GetChildren()

local Enemy = {}
Enemy.__index = Enemy

function Enemy.new(spawnPoint)
	local self = setmetatable({}, Enemy)
	local enemy = Enemy:Spawn(spawnPoint)
	self.Enemy = enemy
	self.Humanoid = enemy:WaitForChild("Humanoid")
	self.Root = enemy:WaitForChild("HumanoidRootPart")
	self.Root:SetNetworkOwner(enemy)
	self.Health = enemy:GetAttribute("Health")
	self.Humanoid.MaxHealth = self.Health
	self.Damage = enemy:GetAttribute("Damage")
	self.Target = nil
	
	return self
end

function Enemy:Init()
	while wait(0.1) do
		if self.Humanoid.Health < 1 then
			break
		end
		self:FindTarget()
		if self.Target then
			self.Humanoid.WalkSpeed = 16
			self:FindPath()
		else
			self.Humanoid.WalkSpeed = 8
			self:Wander()
		end
	end
end

function Enemy:Spawn(spawnPoint)
	local enemy = enemies[math.random(1, #enemies)]:Clone()
	enemy.Parent = workspace
	enemy:SetPrimaryPartCFrame(spawnPoint.CFrame)
	
	return enemy
end

function Enemy:Wander()
	local xRand = math.random(-50, 50)
	local zRand = math.random(-50, 50)
	local goal = self.Root.Position + Vector3.new(xRand, 0, zRand)
	
	local path = PathfindingService:CreatePath()
	path:ComputeAsync(self.Root.Position, goal)
	local waypoints = path:GetWaypoints()
	
	if path.Status == Enum.PathStatus.Success then
		for _, waypoint in ipairs(waypoints) do
			if waypoint.Action == Enum.PathWaypointAction.Jump  then
				self.Humanoid.Jump = true
			end
			self.Humanoid:MoveTo(waypoint.Position)
			local timeOut = self.Humanoid.MoveToFinished:Wait(1)
			if not timeOut then
				print("Enemy Stuck")
				self.Humanoid.Jump = true
				self:Wander()
			end
		end
	else
		print("Path failed")
		self:Wander()
	end
end

function Enemy:CheckSight()
	if self.Target then
		local ray = Ray.new(self.Root.Position, (self.Target.Position - self.Root.Position).Unit * 40)
		local hit, position = workspace:FindPartOnRayWithIgnoreList(ray, {self.Enemy})
		if hit then
			if hit:IsDescendantOf(self.Target) and math.abs(hit.Position.Y - self.Root.Position.Y) < 3 then
				print("Enemy can see the target")
				return true
			end
		end
		return false
	else
		return false
	end
end

function Enemy:FindTarget()
	local distance = 200
	local potentialTargets = {}
	local seeTargets = {}
	for i, v in ipairs(workspace:GetChildren()) do
		local human = v:FindFirstChild("Humanoid")
		local torso = v:FindFirstChild("Torso") or v:FindFirstChild("HumanoidRootPart")

		if human and torso and v.Name ~= self.Enemy.Name then
			if (self.Root.Position - torso.Position).magnitude < distance and human.Health > 0 then
				table.insert(potentialTargets, torso)
			end
		end
	end
	if #potentialTargets > 0 then
		for i, v in ipairs(potentialTargets) do
			if self:CheckSight() then
				table.insert(seeTargets, v)
			elseif #seeTargets == 0 and (self.Root.Position - v.Position).magnitude < distance then
				self.Target = v
				distance = (self.Root.Position - v.Position).magnitude
			end
		end
	end
	if #seeTargets > 0 then
		distance = 200
		for i, v in ipairs(seeTargets) do
			if (self.Root.Position - v.Position).magnitude < distance then
				self.Target = v
				distance = (self.Root.Position - v.Position).magnitude
			end
		end
	end
end

function Enemy:FindPath()
	local path = PathfindingService:CreatePath()
	path:ComputeAsync(self.Root.Position, self.Target.Position)
	local waypoints = path:GetWaypoints()
	
	if path.Status == Enum.PathStatus.Success then
		for _, waypoint in ipairs(waypoints) do
			if waypoint.Action == Enum.PathWaypointAction.Jump then
				self.Humanoid.Jump = true
			end
			self.Humanoid:MoveTo(waypoint.Position)
			local timeOut = self.Humanoid.MoveToFinished:Wait(1)
			if not timeOut then
				self.Humanoid.Jump = true
				self:FindPath()
				break
			end
			if self:CheckSight() then
				repeat
					print("Moving to target")
					self.Humanoid:MoveTo(self.Target.Position)
					wait(0.1)
					if self.Target == nil then
						break
					elseif self.Target.Parent == nil then
						break
					end
				until self:CheckSight() == false or self.Humanoid.Health < 1 or self.Target.Parent.Humanoid.Health < 1
				break
			end
			if (self.Root.Position - waypoints[1].Position).magnitude > 20 then
				print("Target has moved, generating new path")
				self:FindPath()
				break
			end
		end
	end
end

return Enemy

(pastebin code)

local Enemy = require(script.Parent.Enemy)
local PlayerManager = require(script.Parent.PlayerManager)
local spawns = workspace.EnemySpawns:GetChildren()

local function FindSpawnPoint()
	return spawns[math.random(1, #spawns)]
end

PlayerManager.PlayerAdded:Connect(function()
	local enemy = Enemy.new(FindSpawnPoint())
	enemy:Init()
end)

You can see on the video below how does it lag and how easy it is to overtake the enemy and run away

2 Likes
#2

You could replace the wait(0.1) with something like game:GetService('RunService').Heartbeat:wait()

Depending on your code and how frequently Enemy:FindPath() is called this can be really expensive performance-wise (or not)

image

1 Like
#3

It changes enemy movement a bit for better but it is still very visible how slow he is (mostly on changing path when you turn).

1 Like
#4

Raycast from enemy RootPart to target character and if there is a hit then use pathfinding service to find path else if there is no hit that means enemy can just move straightforward

-- wrap this inside loop for example RunService.Heartbeat
EnemyHumanoid:MoveTo(TargetPosition)
1 Like
#5

Okay, makes sense, though where would I put it in my code? Somewhere in Enemy:FindPath()?

1 Like
#6

i havent read the whole module but if Enemy.new() returns created enemy you can simply do

while true do
    Enemy:FindTarget()
    if Enemy.Target then

        local origin = Enemy.PrimaryPart.Position
        local direction = origin - Enemy.Target.PrimaryPart.Position

        local result = workspace:Raycast(origin, direction, raycastparams) -- put params to raycast wont hit enemy

        if result then
            Enemy:FindPath()
        else
            Enemy.Humanoid:WalkTo(Enemy.Target.PrimaryPart.Position)
        end

    end
    RunService.Heartbeat:Wait()
end

wrap that in while loop so Enemy:FindPath() will yield

1 Like
#7

Well, Enemy:Init() handles calling all the functions, so I would rather just add it in FindPath() so there can be 2 options : either change the path or walk forward, right? But I don’t think It will solve the slow movement and slow turning of the enemy, will it?
Somewhere here where we loop thru waypoints

image
image1107×569 63.5 KB

1 Like
#8

i guess raycast from enemy to target inside Enemy:FindPath()

local result = workspace:Raycast(origin, direction, params)
if result then
    -- search for path
else
    Humanoid:MoveTo(Target.PrimaryPart.Position)
end
#9

I’ve implemented it but it didn’t change anything at all. Looking for more solutions

#10

A significant fix was just to remove this

local timeOut = self.Humanoid.MoveToFinished:Wait(1)
if not timeOut then
	self.Humanoid.Jump = true
	self:FindPath()
	break
end
#11

had edited Enemy.new(), Enemy:Init(), Enemy:CheckSight() and Enemy:FindPath() couldnt test so if there is something weird tell me

Module 
local PathfindingService = game:GetService("PathfindingService")
local ServerStorage = game:GetService("ServerStorage")
local RunService = game:GetService("RunService")

local enemies = ServerStorage.Enemies:GetChildren()

local Enemy = {}
Enemy.__index = Enemy

function Enemy.new(spawnPoint)
	local self = setmetatable({}, Enemy)
	local enemy = Enemy:Spawn(spawnPoint)
	local Params = RaycastParams.new()
	Params.FilterType = Enum.RaycastFilterType.Blacklist
	Params.FilterDescendantsInstances = {enemy}
	self.Params = Params
	self.Enemy = enemy
	self.Humanoid = enemy:WaitForChild("Humanoid")
	self.Root = enemy:WaitForChild("HumanoidRootPart")
	self.Root:SetNetworkOwner(enemy)
	self.Health = enemy:GetAttribute("Health")
	self.Humanoid.MaxHealth = self.Health
	self.Damage = enemy:GetAttribute("Damage")
	self.Target = nil

	return self
end

function Enemy:Init()
	while true do
		if self.Humanoid.Health <= 0 then
			break
		end
		self:FindTarget()
		if self.Target and not self:CheckSight() then
			self.Humanoid.WalkSpeed = 16
			self:FindPath()
		elseif self.Target then
			self.Humanoid:WalkTo(self.Target.Position)
		else
			self.Humanoid.WalkSpeed = 8
			self:Wander()
		end
		RunService.Heartbeat:Wait()
	end
end

function Enemy:Spawn(spawnPoint)
	local enemy = enemies[math.random(1, #enemies)]:Clone()
	enemy.Parent = workspace
	enemy:SetPrimaryPartCFrame(spawnPoint.CFrame)

	return enemy
end

function Enemy:Wander()
	local xRand = math.random(-50, 50)
	local zRand = math.random(-50, 50)
	local goal = self.Root.Position + Vector3.new(xRand, 0, zRand)

	local path = PathfindingService:CreatePath()
	path:ComputeAsync(self.Root.Position, goal)
	local waypoints = path:GetWaypoints()

	if path.Status == Enum.PathStatus.Success then
		for _, waypoint in ipairs(waypoints) do
			if waypoint.Action == Enum.PathWaypointAction.Jump  then
				self.Humanoid.Jump = true
			end
			self.Humanoid:MoveTo(waypoint.Position)
			self.Humanoid.MoveToFinished:Wait()
		end
	else
		print("Path failed")
		self:Wander()
	end
end

function Enemy:CheckSight(Position)
	if self.Target or Position then
		self.Params.FilterDescendantsInstances = {
			self.Enemy,
			self.Target
		}
		local origin = self.Root.Position
		local direction = origin - (Position or self.Target and self.Target.Position)
		local result = workspace:Raycast(origin, direction, self.Params)
		if result then
			print("Enemy cant see the target")
			return false
		end
		return true
	else
		return false
	end
end

function Enemy:FindTarget()
	local distance = 200
	local potentialTargets = {}
	local seeTargets = {}
	for i, v in ipairs(workspace:GetChildren()) do
		local human = v:FindFirstChild("Humanoid")
		local root = v:FindFirstChild("HumanoidRootPart")

		if human and root and v.Name ~= self.Enemy.Name then
			if (self.Root.Position - root.Position).magnitude < distance and human.Health > 0 then
				table.insert(potentialTargets, root)
			end
		end
	end
	if #potentialTargets > 0 then
		for i, v in ipairs(potentialTargets) do
			if self:CheckSight() then
				table.insert(seeTargets, v)
			elseif #seeTargets == 0 and (self.Root.Position - v.Position).magnitude < distance then
				self.Target = v
				distance = (self.Root.Position - v.Position).magnitude
			end
		end
	end
	if #seeTargets > 0 then
		distance = 200
		for i, v in ipairs(seeTargets) do
			if (self.Root.Position - v.Position).magnitude < distance then
				self.Target = v
				distance = (self.Root.Position - v.Position).magnitude
			end
		end
	end
end

function Enemy:FindPath()
	if self.Target then
		local path = PathfindingService:CreatePath()
		path:ComputeAsync(self.Root.Position, self.Target.Position)
		local waypoints = path:GetWaypoints()
		if path.Status == Enum.PathStatus.Success then
			for _, waypoint in ipairs(waypoints) do
				if waypoint.Action == Enum.PathWaypointAction.Jump then
					self.Humanoid.Jump = true
				end
				self.Humanoid:MoveTo(waypoint.Position)
				self.Humanoid.MoveToFinished:Wait()
				if self:CheckSight() then
					break
				elseif (self.Root.Position - waypoints[1].Position).magnitude > 20 then
					print("Target has moved, generating new path")
					self:FindPath()
					break
				end
			end
		end
	end
end

return Enemy
#12

It seems to be working just fine but there should be MoveTo instead of WalkTo in the Init() function and also enemy seems to be jumping when chasing a player which looks a bit unnatural, do you know why’s that?

#13

try printing waypoint.Action and see whats wrong