Animation unexpectedly flying apart from the start position

[Fastering18 (sussyt)]

Animation unexpectedly flying apart from the start position

Im making a carry system that plays 2 animations on both the victim and the carrier (carry and idle animation). The script works for first time, but it gives unexpected result after that.

Server script:

local carryEntries = {}

local function weldCarry(carrier : Model, victim : Model)	
	local weld = Instance.new("WeldConstraint")
	weld.Name = "_Carry"
	weld.Parent = carrier
	weld.Part0 = carrier.PrimaryPart
	weld.Part1 = victim.PrimaryPart
	
	victim.Humanoid.AutoRotate = false
	victim.Humanoid.PlatformStand = true
	
	for i, v : BasePart in victim:GetDescendants() do
		if v:IsA("BasePart") then
			v.Massless = true
			v.CanCollide = false
		end
	end
end

local function unweldCarry(char)
	if char:FindFirstChild("_Carry") then
               -- on carrier character
		char._Carry:Destroy()
	else
                -- on victim character
		char.Humanoid.AutoRotate = true
		char.Humanoid.PlatformStand = false
		
		for i, v in char:GetDescendants() do
			if v:IsA("BasePart") then
				v.Massless = false
				v.CanCollide = true
			end
		end
	end
end

animHandler.OnServerInvoke = function(plr, victim) 
  local cached = carryEntries[plr.UserId]
  if cached then
	carryEntries[plr.UserId] = nil
	plr.Character.Humanoid.WalkSpeed = 16
	cached[1].Humanoid.WalkSpeed = 16
	cached[2]:Stop()
	cached[3]:Stop()
	unweldCarry(plr.Character); unweldCarry(cached[1]);
	return true
  end
  if not victim then return false end
	
  local mainChar = plr.Character
  mainChar.Humanoid.WalkSpeed = 0 
  victim.Humanoid.WalkSpeed = 0
	
  local APickerCarry : AnimationTrack = mainChar.Humanoid:LoadAnimation(animationFolder.Picker.Carry)
  local AVictimCarry : AnimationTrack = victim.Humanoid:LoadAnimation(animationFolder.Victim.Carry) 
  local APickerIdle : AnimationTrack = mainChar.Humanoid:LoadAnimation(animationFolder.Picker.Idle)
  local AVictimIdle : AnimationTrack = victim.Humanoid:LoadAnimation(animationFolder.Victim.Idle) 
  carryEntries[plr.UserId] = {victim, APickerIdle, AVictimIdle,}

  -- face the character
  -- mainChar (carrier character model), victim (victim character model)
  victim:PivotTo(CFrame.new(mainChar.PrimaryPart.Position + (mainChar.PrimaryPart.CFrame.LookVector * 6), mainChar.PrimaryPart.Position))
  mainChar:PivotTo(CFrame.new(mainChar.PrimaryPart.Position, victim.PrimaryPart.Position))
	
  -- play both of the animation
  -- fixme: (victim) character unexpectedly moves away from the 
  -- carrier when playing animations below
  APickerCarry:Play() -- "pick the victim"
  AVictimCarry:Play() -- "react to the victim and get carried"
  print((mainChar.PrimaryPart.Position-victim.PrimaryPart.Position).Magnitude) -- 6 studs
	
  APickerCarry.Stopped:Wait()
  print((mainChar.PrimaryPart.Position-victim.PrimaryPart.Position).Magnitude) -- 47 studs

  weldCarry(mainChar, victim)
end

Client LocalScript

local input = game:GetService("UserInputService")
local remoteEvent = game.ReplicatedStorage.anim
local player = game.Players.LocalPlayer

local debounce = false
local isPicking = false
local distance_max = 7 -- in studs

input.InputEnded:Connect(function(key, gs)
	if debounce then return end
	if gs or key.KeyCode ~= Enum.KeyCode.C then return end
	debounce = true
	print("key", gs, key.KeyCode)
	
	if isPicking then
		-- uncarry (no arg needed)
		local success, ret = pcall(remoteEvent.InvokeServer, remoteEvent)
		isPicking = if success and ret then false else true
		print("uncarried")
		
		task.wait(.5)
		debounce = false
		return
	end
	
	for i, v in workspace:GetChildren() do 
		if not v:FindFirstChild("Humanoid") then continue end

		if player.Character and player.Character ~= v and (player.Character.HumanoidRootPart.Position - v.HumanoidRootPart.Position).Magnitude <= distance_max then
			print("found", v)
			
			local success, ret = pcall(remoteEvent.InvokeServer, remoteEvent, v)
			isPicking = if success then ret else false
			
			break
		end
	end
	
	task.wait(.5) 
	debounce = false
end)

no issues with localscript currently

Expected:

This only work when playing the animation on first time

Bug:

The bug is reproducible by playing the animation again

what causes this bug??

[Send_Scripts (Scripty)]

Theres 2 ways you could potentially fix this

1. Weld the player being picked up to the player picking him up
2. Set an attachment inside of the player that is doing the picking up and set an alignposition inside of the player being picked up to that attachment

[Fastering18 (sussyt)]

if v:IsA("BasePart") then
...
v.CanCollide = false

thanks for the replies, i found setting the character bodyparts CanCollide to false makes the animation broken, so using PhysicsService is the best alternative.