VehicleController bug in which the Steer value gets stuck

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#1

I came across a bug recently that I don’t think has been reported about in this forum (I did search). I’m working on a game with vehicles where I’m currently using the out-of-box solution offered with the VehicleSeat object. The bug is that if the player is currently sitting, turns the steering wheel (use arrow keys), and while the steering is turned the player then jumps out, the steering wheel (aka Steer value) will be locked in the direction it was last at when the player sits back into the seat. Note after this bug is present you can turn the steering wheel to the center, but it then snaps back when they “let go”. As far as I can tell there’s not a hacky way to clear this state except to destroy and recreate the VehicleSeat, or in some cases the player can wiggle the steering back and forth (getting in/out of the seat, etc).

I traced what I think is the bug to the PlayerModule->ControlModule->VechicleController script. In VehicleController.lua you have this function:

function VehicleController:Enable(enable, vehicleSeat)
	if enable == self.enabled and vehicleSeat == self.vehicleSeat then
		return
	end

	self.enabled = enable
	self.vehicleMoveVector = ZERO_VECTOR3

	if enable then
		if vehicleSeat then
			self.vehicleSeat = vehicleSeat

			self:SetupAutoPilot()
			self:BindContextActions()
		end
	else
		if useTriggersForThrottle then
			ContextActionService:UnbindAction("throttleAccel")
			ContextActionService:UnbindAction("throttleDeccel")
		end
		ContextActionService:UnbindAction("arrowSteerRight")
		ContextActionService:UnbindAction("arrowSteerLeft")
		self.vehicleSeat = nil
	end
end

If I locally modify the code to the following the problem/bug goes away for me:

function VehicleController:Enable(enable, vehicleSeat)
	if enable == self.enabled and vehicleSeat == self.vehicleSeat then
		return
	end

	self.enabled = enable
	self.vehicleMoveVector = ZERO_VECTOR3

	if enable then
		if vehicleSeat then
			self.vehicleSeat = vehicleSeat

			self:SetupAutoPilot()
			self:BindContextActions()
		end
	else
		if useTriggersForThrottle then
			ContextActionService:UnbindAction("throttleAccel")
			ContextActionService:UnbindAction("throttleDeccel")
		end
		ContextActionService:UnbindAction("arrowSteerRight")
		ContextActionService:UnbindAction("arrowSteerLeft")
		self.turningLeft = 0   -- my added code
		self.turningRight = 0  -- my added code
		self.steer = 0   -- my added code
		self.vehicleSeat = nil
	end
end

The issue most likely happens in other games, but if want to see it in action you can go here and reproduce it:

Hopefully this is helpful, and selfishly I would love to see this fixed is an official release.

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