How to Attach a Rig to a Moving Part without using Weld Constraints

Help and Feedback Scripting Support
1

Auto Swinging Script:

local RunService = game:GetService("RunService")
local CollectionService = game:GetService("CollectionService")
local Players = game:GetService("Players")

local swing = script.Parent
local swing2 = swing.Swing2
local swingSeat2 = swing.SwingSeat2

local bodyForce2 = swingSeat2:FindFirstChild("BodyForce")
if not bodyForce2 then
	bodyForce2 = Instance.new("BodyForce")
	bodyForce2.Parent = swingSeat2
end

local vector3New, clamp, sin = Vector3.new, math.clamp, math.sin
local swingPower = 3
local maxForce = 500
local swingSpeed = 3
local autoTime = 0
local currentOccupant = nil

local function setPhysicalProperties(part, density)
	if part then
		part.CustomPhysicalProperties = PhysicalProperties.new(density, part.Friction, part.Elasticity)
	end
end

local function setCharacterToWeight(toDensity, characterModel)
	for _, desc in pairs(characterModel:GetDescendants()) do
		if desc:IsA("BasePart") then
			setPhysicalProperties(desc, toDensity)
		end
	end
end

local function applySwingForce(part, throttle)
	local force = part.CFrame.LookVector * swingPower * 10 * throttle
	local clampedForce = Vector3.new(
		clamp(force.X, -maxForce, maxForce),
		clamp(force.Y, -maxForce, maxForce),
		clamp(force.Z, -maxForce, maxForce)
	)
	return clampedForce
end

local function seatHumanoid(character, seat)
	local humanoid = character:FindFirstChildOfClass("Humanoid")
	local root = character:FindFirstChild("HumanoidRootPart")
	if humanoid and root and not seat.Occupant then
		humanoid.Sit = true
	end
end

local function onSeat(seat)
	local occupant = seat.Occupant
	local bodyForce = seat:FindFirstChild("BodyForce")
	if not bodyForce then return end

	if occupant then
		local throttle = math.max(0, seat.Throttle)
		bodyForce.Force = applySwingForce(seat, throttle)

		delay(0.2, function()
			bodyForce.Force = vector3New(0, 0, 0)
		end)

		if not currentOccupant then
			currentOccupant = occupant
			local character = currentOccupant.Parent
			
			seatHumanoid(character, seat)
			setCharacterToWeight(0.0001, character)
		end
	end
end

RunService.Heartbeat:Connect(function(dt)
	autoTime = autoTime + dt
	local autoThrottle = math.sin(autoTime * swingSpeed)
	bodyForce2.Force = applySwingForce(swingSeat2, autoThrottle)
end)
2

(use alignorientation too if needed)

or try using motor6d maybe

3

I’ve tried using Motor6D through the script and that didn’t work

4

Please explain why you want to attach it without using WeldConstraints.
If we understood that we may be able to help you out.

Sitting a Humanoid on a VehicleSeat automatically creates a weld between the seat and the player. Obviously your rig is still sitting on the seat, otherwise it’d just fall off. This might be why when you click on the WeldConstraint the Attachment0 and Attachment1 aren’t registering.

Also, BodyForce has been deprecated, you should look at using a VectorForce instead. Check the links below.
Constraints
VectorForce Article
VectorForce Class

For a swing though I’d probably use a HingeConstraint set to Motor placed up at the top of the “rope” where it attaches to the bar. Then apply the W and A inputs to the change the AngularVelocity from + to - so the player and the seat stay aligned with the swing set’s pivot point, just like a real one.

5

The Rig isn’t sitting on the seat it’s placed in seating position on the seat, the Rig does in fact fall off the seat.