How did they make this laser beam

Help and Feedback Scripting Support
#1

How did they make this laser beam? It looks good so I tried to remake it my recreation it doesn’t even work. Can you help me figure out what’s wrong?

local player = game.Players.LocalPlayer
local camera = workspace.CurrentCamera
local rs = game:GetService('RunService')

task.wait(3)

local lasergun = workspace:WaitForChild('lasergun'):Clone()
lasergun.Parent = camera

local debris = game:GetService('Debris')

rs.RenderStepped:Connect(function(dt)
	lasergun:SetPrimaryPartCFrame(camera.CFrame)
	
	local rayorigin = lasergun.tip.Position
	local raydirection = lasergun.tip.CFrame.LookVector * 100
	local param = RaycastParams.new()

	local result = workspace:Raycast(rayorigin, raydirection, param)
	
	if result then
		local part0 = Instance.new('Attachment')
		part0.Parent = lasergun.tip
		part0.Position = result.Position - lasergun.tip.Position
		local part1 = Instance.new('Attachment')
		part1.Parent = lasergun.tip
		part1.Position = (result.Position - lasergun.tip.Position) + Vector3.new(.1,0,.1)

		local trail = workspace.trailpart.Trail:Clone()
		trail.Parent = lasergun.tip
		trail.Attachment0 = part0
		trail.Attachment1 = part1
		
		debris:AddItem(part0, .1)
		debris:AddItem(part1, .1)
		debris:AddItem(trail, .1)
	end
	
end)
#2

it places some sort of part where cursor is and gives it a trail

1 Like
#3

How would I get the parts position to constantly update to where the raycast is without using RunService?

#4

Why would you not want to use RunService? I’m sure a modern computer can handle a single raycast 30-60 times a second just fine.

#5

I want to create a part if there’s a result and then use RunService to update the parts position but I don’t know how to do that without making a part every time theres a raycast which results in me making a bunch of parts that I don’t need

#6

So you haven’t tried creating the part once outside the RunService connection, and then only updating the CFrame in the connection?

#7

Would I shoot the ray inside the RunService connection and then check if there’s a result outside of the connection and then make another RunService connection to update the part’s position? I want to only create the part if there’s a result but I don’t know if you can check outside of the connection

#8

No, do it in the same connection, like this:

local laserHit = ... -- The part
local barrelCFrame = ... -- The front of the barrel, pointing forwards

RunService.Heartbeat:Connect(function()
	-- Cast ray
	local result = workspace:Raycast(barrelCFrame.Position, barrelCFrame.LookVector)
	
	-- Update part position
	laserHit.Position = result.Position
end)

You can change the barrelCFrame variable to be the laser attachment’s CFrame instead if you want it to be slightly more realistic.

1 Like
#9

That worked but my trail keeps moving back towards the barrel whenever I stop moving around

Video of issue

local lasergun = workspace:WaitForChild('lasergun'):Clone()
lasergun.Parent = camera


rs.RenderStepped:Connect(function(dt)
	lasergun:SetPrimaryPartCFrame(camera.CFrame)
	
	local rayorigin = lasergun.tip.Position
	local raydirection = lasergun.tip.CFrame.LookVector * 300

	local result = workspace:Raycast(rayorigin, raydirection)
	
	if result then
		local trailpart = workspace.trailpart
		trailpart.Position = result.Position
	end
	
end)
#10

I just had to turn off cancollide for the part with the trail in it, thanks

#11

why would you need to raycast? you can create part at cursor’s position, it will be the same as raycasting

#12

If you want to optimize, you can instead of raycasting every frame, you can raycast 10 times per second and lerp cursor, this will look similar

#13

I want the laser to be facing where the gun is facing rather than where the mouse is, here is a video of it

1 Like
#14

Can you explain lerping to me? That’s something else I’ve been wanting to learn how to use. If you don’t want to, please send an article/devforum thread I can read

#15

if it’s first person, then it’s the same

#16

It’s simple math

local function LERP(a,b,t)
    return a + (b - a) * t
end

for i = 0, 1, 0.1 do
  -- code
  local pos = LERP(start,finish,i)
end

Lerping is using math to find number between two numbers, for example 5 > 10 where t = 0.5 is 7.5

#17

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.