Is there a way to find out if the player is facing at....

[kevin433]

Hi,

I wanted to know if there is a way to find out if the Player is facing a vehicle or object or something like that.

BTW: I wanted also to ask if there are any limits in MTA. In SA:MP there are Vehicle, object and pickup limits, but are there also limits in MTA?

[lil Toady]

I guess isElementOnScreen would be useful for you to find out if a player is facing some element.

As for the limits, there is an overall limit for the number of elements (vehicles, objects, peds, etc. all together) but i doubt you will ever reach this limit as its over 65000 elements. But there are also some other limits like number of objects in one area (cant remember the numbers) and a number of vehicle models in one area (if i remember right it was about 120 different models, but you are not limited in number of vehicles as long as the number of models does not get over this limit).

So practically you are free to have as many elements as you want as long as they are spread over the map well.

[kevin433]

65000 Elements. I'm never going to reach that

I tried "isElementOnScreen", but it gives me an error:

attempt to call global 'isElementOnScreen' (a nil value)

That's my code:

local x,y,z = getElementPosition(player)
local colsphere = createColSphere(x,y,z,5)
local vehicles = getElementsWithinColShape(colsphere, "vehicle")
for i,vehicles2 in ipairs(vehicles) do
if(isElementOnScreen(vehicles2)) then
outputChatBox(getElementID(vehicles2))
end
end

There's more above it in my script, but in that part is the error. I'm using a commandhandler to call the function. When I take out "if(isElementOnScreen(vehicles2)) then" everything works fine.

EDIT: Found one wrong thing, I called the function "isElementOnScreen" in a Server-side file

Edited February 25, 2010 by Guest

[Aibo]

i bet that's server side script, while isElementOnScreen is obviously a client-only function.

[kevin433]

I made it now Client-side, but it's still not working

function OpenCar()
local x,y,z = getElementPosition(getLocalPlayer())
local newcolsphere = createColSphere(x,y,z,5)
local vehicles = getElementsWithinColShape(newcolsphere, "vehicle")
for theKey,vehicles2 in ipairs(vehicles) do
if(isElementOnScreen(vehicles2)) then
outputChatBox(getElementID(vehicles2))
end
end
end

BTW: I'm still learning the generic for loop.

[Buffalo]

Please note that for legacy reasons, a colshape created on the client does not collide with elements already existing at that location until they first move

Maybe you should retrieve this vehicles table server side, then triggerClientEvent() and send it to client side, then proceed check with loop and isElementOnScreen()

[kevin433]

The only problem is then that I can't get the Player who triggered the event, because I triggered the "OpenCar" function with a GUI button , but a button doesn't "send" the player with it. So I would have to do this: Press Button -> triggerSeverEvent -> vehicle loop -> triggerClientEvent -> isElementOnScreen. But as I said I can't get the player who triggered the event, or can I?

[Buffalo]

It's always local player, which you can get with getLocalPlayer(), and you should use triggerServerEvent(string:eventName,getLocalPlayer(),args..), so event source would be local player

[kevin433]

That's how far I came:

GUI Button -> triggerServerEvent -> get elementID's near the player -> ???

I didn't came further than in the example above.

Client side:

-- Player click a button, then OpenCar gets triggered
function OpenCar()
triggerServerEvent("CVehicles", getLocalPlayer())
end

Server-side:

function CheckVehiclesNear()
local x,y,z = getElementPosition(source)
local newcolshape = createColSphere(x, y, z,5)
local vehicles = getElementsWithinColShape(newcolshape, "vehicle")
for theKey,vehicles2 in ipairs(vehicles) do
outputChatBox(getElementID(vehicles2))
end
destroyElement(newcolshape)
triggerClientEvent(source,"COnScreen", getRootElement(), vehicles2)
end
addEvent("CVehicles", true)
addEventHandler("CVehicles", getRootElement(), CheckVehiclesNear)

Client-side. tried it, but it didn't work:

function CarOnScreen(vehicles)
for theKey,vehicles2 in ipairs(vehicles) do
if(isElementOnScreen(vehicles2)) then
outputChatBox(getElementID(vehicles2))
end
end
end
addEvent("COnScreen", true)
addEventHandler("COnScreen", getRootElement(), CarOnScreen)

Should I maybe set the "triggerClientEvent in the loop in the Server-side script?

[lil Toady]

You dont need all the fancy server-client event calls, just get the closest vehicles looping through all of them (getElementsByType("vehicle")) and comparing distance between the vehicle and local player(getDistanceBetweenPoints3D), if its close, check if its on screen.

[kevin433]

Have this now:

function OpenCar()
local x,y,z = getElementPosition(getLocalPlayer())
for i,vehicle in ipairs(getElementsByType("vehicle")) do
local vx,vy,vz = getElementPosition(vehicle)
if(getDistanceBetweenPoints3D(x,y,z,vx,vy,vz) <= 4) then
if(isElementOnScreen(vehicle)) then
outputChatBox(getElementID(vehicle))
end
end
end
end

It works!

Problem now: I want to get the ID of the Vehicle the player is looking at, because, when I stand between 2 vehicles and both are <=4 then I get both ID's, but I just want to get the one which I'm looking at, that's why I added "isElementOnScreen", but I get both ID's when I stand between them and I just look at one of them while the other car is "behind" my camer.

[lil Toady]

Strange it hasnt passed the vehicles you dont see. But anyway. You could drop the loop at all and instead shoot a process line of sight in the direction the player is facing for the distance you want.

local x, y, z = getElementPosition ( player )
local rot = getPedRotation ( player )
local radius = 4
local lx = x + math.sin ( math.rad ( -rot ) ) * radius
local ly = y + math.cos ( math.rad ( -rot ) ) * radius
local hit, hx, hy, hy, element = processLineOfSight ( x, y, z, lx, ly, z )
if ( hit and getElementType ( element ) = "vehicle" ) then
-- 'element' is the vehicle you need
end

[kevin433]

Thank you very much,lil Toady! It finally works!