How to make AssemblyLinearVelocity sync with Tween movement?

[SpectralTunnelz]

Hello, scripters! I’m working on escalator script. I have noticed that it moves itself but it doesn’t move you. Is there anyway to sync AssemblyLinearVelocity with Tween movement perfectly using scripts?

Also how to sync AssemblyLinearVelocity with Tween movement if it has different EasingStyle?

[EmmieShayz (Emmie)]

I’m not sure there’s a reliable way to “sync” AssemblyLinearVelocity with a CFrame/Position tween. I’m not sure what sync would even mean in this case, but they’re different systems. The physics engine, in my understanding, should be independent from TweenService, so trying to align the player to it with physics doesn’t really make sense to me.

What I would suggest is something like this:

• Player touches escalator
  • connect to RunService.Heartbeat
    • compare previous escalator part position to the current one
    • add the position difference to player’s root part

This should make sure the player stays on the escalator no matter where it moves, as every frame it will re-position the player to account for the change in position that the escalator faces.

[Vikko151]

@EmmieShayz

I’m not sure there’s a reliable way to “sync” AssemblyLinearVelocity with a CFrame/Position tween.

Personally, your best bet would be to use AlignPosition and AlignOrientation, but if you want to stick with tweens, you can try to inspire yourself from this post:

@Kord_K

This is what I do and my version works pretty well.

local Players = game:GetService("Players")
local player = game.Players.LocalPlayer
local RunService = game:GetService('RunService')

local LastTrainCFrame

local Function
local Function2


Function = RunService.Heartbeat:Connect(function()

--------------------------------------------------------------- CHECK PLATFORM BELOW

local RootPart = player.Character.LowerTorso

local Ignore = player.Character

local ray = Ray.new(RootPart.CFrame.p,Vector3.new(0,-50,0))

local Hit, Position, Normal, Material = workspace:FindPartOnRay(ray,Ignore)

if Hit and Hit.Name == "RaftTop" then -- Change "RaftTop" to whatever the moving part's name is

--------------------------------------------------------------- MOVE PLAYER TO NEW POSITON FROM OLD POSITION

local Train = Hit
if LastTrainCFrame == nil then -- If no LastTrainCFrame exists, make one!
	LastTrainCFrame = Train.CFrame -- This is updated later.
end
local TrainCF = Train.CFrame 

local Rel = TrainCF * LastTrainCFrame:inverse()

LastTrainCFrame = Train.CFrame -- Updated here.

RootPart.CFrame = Rel * RootPart.CFrame -- Set the player's CFrame
--print("set")

else
LastTrainCFrame = nil -- Clear the value when the player gets off.

end

Function2 = player.Character.Humanoid.Died:Connect(function()
	Function:Disconnect() -- Stop memory leaks
	Function2:Disconnect() -- Stop memory leaks
end)

end)

In my case, ‘RaftTop’ is the bright, large plank of wood on top of the raft. Slightly hard to see in the video but the player does turn with the platform. The player can jump on while it’s moving and move with it, it works just as the Jailbreak trains do. Also yes, I was testing a raft with no water. I know it looks ugly.

//devforum-uploads.s3.dualstack.us-east-2.amazonaws.com/uploads/original/5X/b/f/d/0/bfd0e0979748a83ec9cfb9c230fb528a11e0e53c.mp4

Hope I could help! Feel free to ask any other questions if you need extra help or if something doesn’t work.

Oh, and as a note, you can also use magnitude to see if the player is jumping or not. This can make the physic look more realistic.

If you need assistance to code such a thing, tell me!

[EmmieShayz (Emmie)]

@Kord_K

local Rel = TrainCF * LastTrainCFrame:inverse()

LastTrainCFrame = Train.CFrame -- Updated here.

RootPart.CFrame = Rel * RootPart.CFrame -- Set the player's CFrame

Looks like the same logic I suggested about adding the position difference, but also accounting for the rotation via the use of cframes. Neat.

@Vikko151

Oh, and as a note, you can also use magnitude to see if the player is jumping or not. This can make the physic look more realistic.

Not clear what you’re actually suggesting here. If you’re talking about disabling the “add the difference” logic when you’re in mid-air, then yeah I agree. But I’m also not sure about which magnitude you’re talking about.

Also the post you referenced has some very, very old code. It can help with figuring out how to do this, but I wouldn’t copy the exact language it uses.

[Vikko151]

@EmmieShayz

Not clear

As always lol.

@EmmieShayz

If you’re talking about disabling the “add the difference” logic when you’re in mid-air, then yeah I agree. But I’m also not sure about which magnitude you’re talking about.

By Magnitude, I forgot to mention it’s like (A.Position - B.Position).Magnitude. But theorically, she can just watch if the Humanoid’s state is set to another state than Humanoid.State.Running or Humanoid.State.Running.

@EmmieShayz

Also the post you referenced has some very, very old code. It can help with figuring out how to do this, but I wouldn’t copy the exact language it uses.

It’s why I said that she should inspire herself from that. Agree that the code hurt my eyes a bit, but the concept is still good.

[SpectralTunnelz]

Hmmm… Okay thank you anyways
I only know how to sync AssemblyAngularVelocity with rotating part by tween:

local ts = game:GetService('TweenService')
local part = script.Parent
local AssemblyAngularVelocitySpeed = 2
local rad = 120/AssemblyAngularVelocitySpeed

while true do
   ts:Create(part,TweenInfo.new(math.rad(rad),Enum.EasingStyle.Linear),
       {CFrame = part.CFrame * CFrame.Angles(0,math.rad(120),0}):Play()
   task.wait(math.rad(rad))
end

There’s special formula: AssemblyAngularVelocitySpeed = 120/rad
Now I’m trying to figure out same with AssemblyLinearVelocitySpeed.
I’ll be experimenting with PrismaticConstraint to see.