Attach existing trailer to existing vehicle

[ivan8065]

Hello, I am trying to make script that would allow me connect existing trailer to existing vehicle. I am working with example from here https://wiki.multitheftauto.com/wiki/AttachTrailerToVehicle and I managed to make trailer spawn to existing car but I don't know how define trailer so it will connect trailer that is spawned nearby to my car. Thank you for any help.

 

setTimer(
	function()
		local vehicle = getPedOccupiedVehicle( localPlayer )
		local x,y,z = getElementPosition( vehicle )
		local rx,ry,rz = getElementRotation ( vehicle )
		local trailer = 
		attachTrailerToVehicle ( vehicle, trailer )   -- attach then
		outputChatBox("Connected.", 255, 0, 0)
	end, 50, 1)

 

[SpecT]

Hey,

There is a "useful" function on the wiki to get the nearest vehicle to a player by specified max distance - getNearestVehicle.
You can use it for your script but it will need a check whether the vehicle type is "trailer".

Something like this:

function getNearestTrailer(player,distance)
	local lastMinDis = distance-0.0001
	local nearestTrailer = false
	local px,py,pz = getElementPosition(player)
	local pint = getElementInterior(player)
	local pdim = getElementDimension(player)

	for _,v in pairs(getElementsByType("vehicle")) do
		local vint,vdim = getElementInterior(v),getElementDimension(v)
		if vint == pint and vdim == pdim then
			local vx,vy,vz = getElementPosition(v)
			local dis = getDistanceBetweenPoints3D(px,py,pz,vx,vy,vz)
			if dis < distance then
				if dis < lastMinDis and getVehicleType(v) == "trailer" then 
					lastMinDis = dis
					nearestTrailer = v
				end
			end
		end
	end
	return nearestTrailer
end

And then use it like:

getNearestTrailer(localPlayer, 50)

 

Edited July 19, 2021 by SpecT

[ivan8065]

I hope I got it correctly like this

function getNearestTrailer(player,distance)
	local lastMinDis = distance-0.0001
	local nearestTrailer = false
	local px,py,pz = getElementPosition(player)
	local pint = getElementInterior(player)
	local pdim = getElementDimension(player)

	for _,v in pairs(getElementsByType("vehicle")) do
		local vint,vdim = getElementInterior(v),getElementDimension(v)
		if vint == pint and vdim == pdim then
			local vx,vy,vz = getElementPosition(v)
			local dis = getDistanceBetweenPoints3D(px,py,pz,vx,vy,vz)
			if dis < distance then
				if dis < lastMinDis and getVehicleType(v) == "trailer" then 
					lastMinDis = dis
					nearestTrailer = v
				end
			end
		end
	end
	return nearestTrailer
end

function hookTrailer(commandName)
		vehicle = getPedOccupiedVehicle(localPlayer)
		local x,y,z = getElementPosition( vehicle )
		local rx,ry,rz = getElementRotation ( vehicle )
		trailer = getNearestTrailer(localPlayer, 50)
		attachTrailerToVehicle ( vehicle, trailer )
		outputChatBox("Connected.", 255, 0, 0)
	end
addCommandHandler("hook", hookTrailer)

because I got warning

WARNING: trailer/trailer.lua:29: Bad argument @ 'attachTrailerToVehicle' [Expected vehicle at argument 2, got boolean]

 

[SpecT]

It throws you this error cuz it couldn't find a trailer. Maybe the distance is too low (50) you can try by increasing it and test.

Edited the function a bit to prevent eventual errors.

function hookTrailer(commandName)
	local vehicle = getPedOccupiedVehicle(localPlayer)
  	if vehicle then
		local x,y,z = getElementPosition( vehicle )
		local rx,ry,rz = getElementRotation ( vehicle )
		local trailer = getNearestTrailer(localPlayer, 50)
		if trailer then
			attachTrailerToVehicle ( vehicle, trailer )
			outputChatBox("Connected.", 255, 0, 0)
		else
			outputChatBox("No nearby trailer was found!", 255, 0, 0)
		end
	else
		outputChatBox("You need to be in a vehicle!", 255, 0, 0)
	end
end
addCommandHandler("hook", hookTrailer)

*Edit: BTW I just thought about it that this probably is not gonna work as it is made in the client-side.
Vehicles created in client-side cannot be entered but only be shown.
So I guess your vehicles (truck and trailer) are spawned from server side ?
You will need to make the script server-sided. It's not hard but if you struggle don't hesitate to ask for assistance.

Edited July 19, 2021 by SpecT

[ivan8065]

I am trying to make it server-sided but in debug I have warnings from last 3 lines saying "Expected element at argument 1, got nil" and it is saying same thing if it's there player or thePlayer.

function getNearestTrailer(player,distance)
	local lastMinDis = distance-0.0001
	local nearestTrailer = false
	local px,py,pz = getElementPosition(player)
	local pint = getElementInterior(player)
	local pdim = getElementDimension(player)

 

[SpecT]

Show me how do you call the function "getNearestTrailer".

In server-side there is no "localPlayer". Keep that it mind.

[ivan8065]

Yeah sorry my fault. I changed it from localPlayer to thePlayer, even tried vehicle and now I don't have any errors or warnings but after using command it still wont attach trailer to vehicle and changing distance didn't help.

function getNearestTrailer(thePlayer,distance)
	local lastMinDis = distance-0.0001
	local nearestTrailer = false
	local px,py,pz = getElementPosition(thePlayer)
	local pint = getElementInterior(thePlayer)
	local pdim = getElementDimension(thePlayer)

	for _,v in pairs(getElementsByType("vehicle")) do
		local vint,vdim = getElementInterior(v),getElementDimension(v)
		if vint == pint and vdim == pdim then
			local vx,vy,vz = getElementPosition(v)
			local dis = getDistanceBetweenPoints3D(px,py,pz,vx,vy,vz)
			if dis < distance then
				if dis < lastMinDis and getVehicleType(v) == "trailer" then 
					lastMinDis = dis
					nearestTrailer = v
				end
			end
		end
	end
	return nearestTrailer
end

function hookTrailer(thePlayer,commandName)
	local vehicle = getPedOccupiedVehicle ( thePlayer )
  	if vehicle then
		local x,y,z = getElementPosition( vehicle )
		local rx,ry,rz = getElementRotation ( vehicle )
		local trailer = getNearestTrailer(thePlayer, 2000)
		if trailer then
			attachTrailerToVehicle ( vehicle, trailer )
			outputChatBox("Connected.", thePlayer, 0, 255, 0)
		else
			outputChatBox("No nearby trailer was found!", thePlayer, 255, 0, 0)
		end
	else
		outputChatBox("You need to be in a vehicle!", thePlayer, 255, 0, 0)
	end
end
addCommandHandler("hook", hookTrailer)

 

[SpecT]

Hey,

I had to test it in-game and found what was wrong - getVehicleType returns the type as string but capitalized (lol).

Replace with:

getVehicleType(v) == "Trailer"

Also you will need to lower the distance cuz 2000 is way too much (tested it with 200 and it was attaching it from far). 

Edited July 20, 2021 by SpecT

[ivan8065]

WOW man, it really works! Thank you very much!