Tank game: Issue with Fastcast hit detection, and weld manipulation | Suphi Kaner | Page 1

timid breach Jul 28, 2023, 9:17 PM

#

https://devforum.roblox.com/t/tank-game-issue-with-fastcast-hit-detection-and-weld-manipulation/2491835

Developer Forum | Roblox

Tank game: Issue with Fastcast hit detection, and weld manipulation

So I’m making a multi-crew tank game where you hop on inside the tank and control different crew roles. I have based the gun/turret rotation based off this concept, where you basically send a remote to the server, telling it where you want to rotate the turret (Weld.C1.Angles property), and sending back the remote to all the clients except the ...

scenic musk Jul 29, 2023, 3:53 AM

#

from my experience with fastcast never try and simulate anything on the client all simulation should be done on the server

#

this is from the creator of fast cast

#

no need to read all this basically he says do it on the server

#

as for ur issue u'll have to do the rotation of the shooting point attachment on the server as well

#

or u could also ask the client where the bullets orgin should be shouldnt really affect anything

marble tulip Jul 29, 2023, 2:29 PM

#

only do fastcast client side for stuff like client side particle effects

#

so there isnt a weird delay

#

but all damage calculations should be server

timid breach Jul 30, 2023, 3:21 PM

#

scenic musk or u could also ask the client where the bullets orgin should be shouldnt really...

cant exploiters just fire wherever they want

scenic musk Jul 30, 2023, 3:21 PM

#

timid breach cant exploiters just fire wherever they want

no

timid breach Jul 30, 2023, 3:21 PM

#

also so sorry for late response

scenic musk Jul 30, 2023, 3:21 PM

#

u are also asking the client where they are firing from

#

say its a gun

#

the way fastcast works u have attachment in gun they have network ownership of

#

so u they can do whatever they want with anything they own

timid breach Jul 30, 2023, 3:24 PM

#

well um idk if what i did rn was necessary but im making entirely separate folder and making cloned, fake tank and pivoting them where the OG tank is from the server

#

red is fake and normally colored is real

#

the red acts like hitbox

scenic musk Jul 30, 2023, 3:25 PM

#

uh

timid breach Jul 30, 2023, 3:25 PM

#

the red is slightly behind for the driver, the network owner which is normal right

scenic musk Jul 30, 2023, 3:25 PM

#

yeah

#

well

#

it should also work

timid breach Jul 30, 2023, 3:26 PM

#

the other players see the red tank forward to where the tank goes

#

is it also normal?

scenic musk Jul 30, 2023, 3:27 PM

#

why dont u just use the tank on the server then?

timid breach Jul 30, 2023, 3:27 PM

#

which one?

scenic musk Jul 30, 2023, 3:28 PM

#

reds only a hitbox and tank on server is the visual representation of tank?

timid breach Jul 30, 2023, 3:28 PM

#

red is what server sees the tank like tho right?

scenic musk Jul 30, 2023, 3:29 PM

#

ohh i had it the other way around

#

its normal for the one on the server to lag behind a little

timid breach Jul 30, 2023, 3:30 PM

#

the red one will not be visible to others

#

but like

#

if an enemy gunner aims at your tank

#

he sees it in entirely different position as you do

#

but none see it the way the server (red) does

scenic musk Jul 30, 2023, 3:31 PM

#

well

#

im completely confused

#

however how i would do it is give ownership of tank to the one driving the tank

timid breach Jul 30, 2023, 3:31 PM

#

me too

timid breach Jul 30, 2023, 3:31 PM

#

scenic musk however how i would do it is give ownership of tank to the one driving the tank

already doing that

scenic musk Jul 30, 2023, 3:31 PM

#

and ask the client to manipulate pointing direction and everything around those lines

#

only i would use the server to fire the bullet when the client asks

timid breach Jul 30, 2023, 3:33 PM

#

do you wanna playtest my game so you can figure out more stuff? if you want

scenic musk Jul 30, 2023, 3:33 PM

#

i would ask the server to tell me what ive hit

scenic musk Jul 30, 2023, 3:33 PM

#

timid breach do you wanna playtest my game so you can figure out more stuff? if you want

ok

#

send

timid breach Jul 30, 2023, 3:33 PM

#

u gotta join a group because its locked to testers

#

https://www.roblox.com/groups/15194289/Steel-Projects

Roblox

Steel Projects

Steel Projects is a group on Roblox owned by SteelProjects_Holder with 37 members. hi

#

i will make you one

scenic musk Jul 30, 2023, 3:34 PM

#

ok

#

Creator_Rat < my username

timid breach Jul 30, 2023, 3:35 PM

#

https://www.roblox.com/games/11750427321/Steel-Commanders

Roblox

Steel Commanders

Check out Steel Commanders. It’s one of the millions of unique, user-generated 3D experiences created on Roblox. in development

timid breach Jul 30, 2023, 3:51 PM

#

u good?

scenic musk Jul 30, 2023, 3:52 PM

#

timid breach u good?

wdym?

timid breach Jul 30, 2023, 3:52 PM

#

you left

scenic musk Jul 30, 2023, 3:52 PM

#

yeah well i didnt think i needed to stay

timid breach Jul 30, 2023, 3:53 PM

#

come back you misunderstood what i meant

scenic musk Jul 30, 2023, 3:53 PM

#

tell me here pls

timid breach Jul 30, 2023, 3:53 PM

#

when you said player should tell where bullet should come from

#

you were right

#

but like

#

when the bullet begins to simulate on the server

#

there are other enemy tanks who have rotated their turrets

#

which change entire physical layout

#

the bullet does not know how the enemy tanks look like

#

they always think they are oriented at 0 angle

#

but that wouldnt be true

#

this is why i made the red hitbox thing

scenic musk Jul 30, 2023, 3:55 PM

#

if the tank is owned by the character driving then the tank will rotate

#

if u go to studio

#

and rotate a part that u have ownership of it will rotate for everyone aswell

timid breach Jul 30, 2023, 3:55 PM

#

the gunner does not have ownership of the tank

#

the driver does

#

and the gunner the one who rotates the turret

scenic musk Jul 30, 2023, 3:55 PM

#

oh i see

timid breach Jul 30, 2023, 3:56 PM

#

if i give ownership to gunner

#

rotation problem is sovled

#

but driver would lag

scenic musk Jul 30, 2023, 3:56 PM

#

but the tank will lag behind

#

yeah

timid breach Jul 30, 2023, 3:57 PM

#

while task.wait(0.033) do
    if script.Parent then
        if runService:IsRunning() then
            TurretRenderingEvent:FireServer(desiredTurretAngle, desiredGunAngle)
        end
    end
end

#

this is what the gunner client is doing

#

function RenderTurretForClients(plyr, gunRot, turrRot)
    local GunStats = TankStatsDictionary[plyr.Tank.Name].GunStats

    if GunStats.GunUpperAngle >= gunRot and GunStats.GunLowerAngle <= gunRot then
        local SeatPart = hum.SeatPart

        if SeatPart then
            if SeatPart.Name == "GunnerVehicleSeat" then
                for i, player in ipairs(Players:GetPlayers()) do
                    if player ~= plyr then
                        TurretRenderingEvent:FireClient(player, turrRot, gunRot, SeatPart)
                    end
                end    
            end
        end
    end
end
TurretRenderingEvent.OnServerEvent:Connect(RenderTurretForClients)

#

and how the server responds

#

^this is the important part

#

it sends remote to tell the other clients EXCEPT the gunner who rotated (because he already rotated it on his own client) to rotate the turret for themselves

#

-- Other clients
local function RenderTurret(gunRot: number, turrRot: number, seatPart: VehicleSeat)
   -- This does not run for the client rotating the turret
    if turrRot then
        seatPart.TurretRotation.C1 = CFrame.Angles(0, math.rad(turrRot), 0)
    end
    if gunRot then
        seatPart.Elevation.C1 = CFrame.Angles(math.rad(gunRot), 0, 0)
    end
end
TurretRenderingEvent.OnClientEvent:Connect(RenderTurret)

scenic musk Jul 30, 2023, 4:00 PM

#

well

#

this is the obvious fix

timid breach Jul 30, 2023, 4:01 PM

#

and the issue gets even worse if i want to have multiple turrets in 1 assembly (1 tank)

timid breach Jul 30, 2023, 4:01 PM

#

scenic musk this is the obvious fix

i would love to know it

scenic musk Jul 30, 2023, 4:02 PM

#

well looks like someone in the devforums already has solved this

#

https://www.roblox.com/games/3343002014/Tank-Experiment-Uncopylocked

Roblox

Tank Experiment - Uncopylocked

Check out Tank Experiment - Uncopylocked. It’s one of the millions of unique, user-generated 3D experiences created on Roblox. Little experiment about network ownership and sharing for a tank turret - inspired by this post

https://devforum.roblox.com/t/a-way-to-split-model-network-owner/

#

https://devforum.roblox.com/t/a-way-to-split-model-network-owner/295877/18

Developer Forum | Roblox

A way to split model network owner?

Source code should be pretty easy to figure out what is going on.

timid breach Jul 30, 2023, 4:02 PM

#

scenic musk https://devforum.roblox.com/t/a-way-to-split-model-network-owner/295877/18

this is EXACTLY what my code does

#

i got the idea from this guy

scenic musk Jul 30, 2023, 4:02 PM

#

im sure there is a simpler fix

timid breach Jul 30, 2023, 4:02 PM

#

timid breach https://devforum.roblox.com/t/tank-game-issue-with-fastcast-hit-detection-and-we...

i even say it in my post

scenic musk Jul 30, 2023, 4:03 PM

#

well

timid breach Jul 30, 2023, 4:03 PM

#

maybe i didnt read his code correctly im gonna do it again

scenic musk Jul 30, 2023, 4:03 PM

#

if it works it works no need to think further

timid breach Jul 30, 2023, 4:04 PM

#

scenic musk if it works it works no need to think further

btw if you know how does multicrew tank combat handle it?

scenic musk Jul 30, 2023, 4:04 PM

#

probably the same way

#

if it works for 1 it works for all

timid breach Jul 30, 2023, 4:05 PM

#

client

#

server

#

scenic musk Jul 30, 2023, 4:06 PM

#

rotate it on the server too

#

although it will not in sync

timid breach Jul 30, 2023, 4:07 PM

#

scenic musk rotate it on the server too

this will not work unfortunately

#

i mean it will

#

but its going to mess up the controls

#

also if u wanna know this guy uses welds

#

weld manipulation

#

and idk if the server replicates changes to Weld.C1 if the assembly network owner does it

scenic musk Jul 30, 2023, 4:08 PM

#

timid breach but its going to mess up the controls

change ur controls a little bit then

timid breach Jul 30, 2023, 4:09 PM

#

scenic musk change ur controls a little bit then

the server will set the angles and it will do it more slowly than the client rotates turret

#

which will result in turret not moving almost at all

scenic musk Jul 30, 2023, 4:10 PM

#

timid breach the server will set the angles and it will do it more slowly than the client rot...

u can get an estimate of it by sending in the time u recieved the remote event

timid breach Jul 30, 2023, 4:10 PM

#

jittering over and over

timid breach Jul 30, 2023, 4:10 PM

#

scenic musk u can get an estimate of it by sending in the time u recieved the remote event

exploiter can send whatever they want

scenic musk Jul 30, 2023, 4:10 PM

#

yeah

#

well

#

another option would be to switch network ownership between turret and driver

#

when the turret user rotates the turret

#

but the problem with that is it will jitter mid way

timid breach Jul 30, 2023, 4:11 PM

#

yep

#

im starting to lose hope now

#

ferrarico and mtc found a solution to this

scenic musk Jul 30, 2023, 4:12 PM

#

what was their solution

timid breach Jul 30, 2023, 4:12 PM

#

the only way is they used fastcast on the client

scenic musk Jul 30, 2023, 4:12 PM

#

oh actually

timid breach Jul 30, 2023, 4:12 PM

#

and SOMEHOW used the server to verify the hits

scenic musk Jul 30, 2023, 4:12 PM

#

yeah u can do that

#

u can use it on the client and ask the server to verify the hits but

#

me personally im not a huge fan of that since the bullets will replicate at different rates

#

although for something like a tank missile or whatnot it shouldnt matter too much

timid breach Jul 30, 2023, 4:13 PM

#

the only circumstance it would not matter if the weapon was hitscan

scenic musk Jul 30, 2023, 4:14 PM

#

scenic musk oh actually

i think one other solution would be to use a click shoot system where the turret rotates to where they click this way u can ask the client where they want to rotate

#

and ask the server to ask the client driving to rotate the turret

#

this way it will replicate for all

#

although idk what u have going on

timid breach Jul 30, 2023, 4:15 PM

#

scenic musk and ask the server to ask the client driving to rotate the turret

Weld.C1 does not replicate changes

scenic musk Jul 30, 2023, 4:15 PM

#

oh it does not?

timid breach Jul 30, 2023, 4:15 PM

#

even if network owner

#

i thinkkkk

scenic musk Jul 30, 2023, 4:15 PM

#

wait i dont think so

#

yk those

#

tool character

#

things

#

where theres tool on character

#

um

#

actually nvm that might be done on the client i think thats how i did it

timid breach Jul 30, 2023, 4:16 PM

#

#

driver pov (network owner) sees it like this

scenic musk Jul 30, 2023, 4:16 PM

#

ok

#

and server?

timid breach Jul 30, 2023, 4:16 PM

#

scenic musk Jul 30, 2023, 4:16 PM

#

change it on the server?

#

maybe?

timid breach Jul 30, 2023, 4:17 PM

#

timid breach Jul 30, 2023, 4:17 PM

#

scenic musk maybe?

wdym

scenic musk Jul 30, 2023, 4:17 PM

#

change the c1 rotation on the server

#

i think it might instantly change back

#

but if u use renderstepped to change it and hold it there it could work

timid breach Jul 30, 2023, 4:18 PM

#

wait

#

um

#

can you show me soem code that does this

#

because i tried something similar

#

and idk if i did correct

#

ly

scenic musk Jul 30, 2023, 4:19 PM

#

lastRotation = 0

--We need to do this since the client owns the tank, it will only change for 1 frame and go back
RunService.RenderStepped:Connect(function()
  weld.C1.Orientation = lastRotation
end)

--this to change current orientation
changePivot.Onserverevent:connect(function(localNewrotation)
  lastRotation = localNewrotation
end)```

timid breach Jul 30, 2023, 4:20 PM

#

i did something similar but it didnt work but i'll try again

scenic musk Jul 30, 2023, 4:20 PM

#

see if it works

timid breach Jul 30, 2023, 4:20 PM

#

if this works you're a lifesaver

scenic musk Jul 30, 2023, 4:20 PM

#

well

#

i try to be

timid breach Jul 30, 2023, 4:20 PM

#

im not doing it rn i've been coding the red thingy for 3 hours

#

gonna take a break

scenic musk Jul 30, 2023, 4:21 PM

#

good thing to take breaks

#

i will say

timid breach Jul 30, 2023, 4:21 PM

#

im gona tell you the results

scenic musk Jul 30, 2023, 4:21 PM

#

this is far worse in performance

#

in comparsion to what they did

#

since in the server

#

u will have to basically reset the oreintation

#

every frame

#

so the more tanks u have the more worse the performance will get probably

#

it is far better to go with the previous option and do fastcast in the client

#

and instead of fastcast i would probably do hitscan as well

#

the reason for this is bc ur projectiles are very fast and dont really require physics simulation

timid breach Jul 30, 2023, 4:22 PM

#

they go like 1.5k studs/s

#

or 1k

scenic musk Jul 30, 2023, 4:22 PM

#

thats a lot of speed

timid breach Jul 30, 2023, 4:23 PM

#

but they got bullet drop man

scenic musk Jul 30, 2023, 4:23 PM

#

which basically means its just a straight line

#

u dont need bullet drop

#

they go too fast

#

they go beyond u can render at once anyway

scenic musk Jul 30, 2023, 4:23 PM

#

scenic musk ```lua lastRotation = 0 --We need to do this since the client owns the tank, it...

i would entirely recommend u dont do this actually since its horrible practice

timid breach Jul 30, 2023, 4:24 PM

#

lkemdelkdeadmgjkernoginregmrwgoerwgre

scenic musk Jul 30, 2023, 4:24 PM

#

stop using fastcast

#

and use hitcast

timid breach Jul 30, 2023, 4:24 PM

#

where is security mtc has omg

scenic musk Jul 30, 2023, 4:25 PM

#

i dont know man i dont know who that one is

#

but what i do know is fastcast is basically useless and worse in performace for ur needs

#

switch to just hitscan type detection

#

aka 1 straight line ray

timid breach Jul 30, 2023, 4:27 PM

#

idk im not sure

#

the game needs bullet drop

timid breach Jul 30, 2023, 4:27 PM

#

scenic musk i would entirely recommend u dont do this actually since its horrible practice

doesnt seem like it

#

basically the only 2 solutions is client fastcast and this

scenic musk Jul 30, 2023, 4:27 PM

#

if ur game does need bullet drop then

#

go for it

timid breach Jul 30, 2023, 4:28 PM

#

what if i do 2 fastcast at same time???

#

one in the client and one in the server

scenic musk Jul 30, 2023, 4:28 PM

#

thats what u are doing

#

something like that actually

#

since u need to validate the hit in the server somehow

#

well

#

in my opinion, for ur needs

#

hitscans better

#

tank bullets are very fast

#

but if u were to do this then do it on the server and the client each have their own pros and cons

timid breach Jul 30, 2023, 4:29 PM

#

wait

#

is there a way to build a system to like

#

rewind physics

scenic musk Jul 30, 2023, 4:30 PM

#

yeah

#

u can just

#

fastcast from endpoint bnack to origin

timid breach Jul 30, 2023, 4:30 PM

#

to check if a hit should have really hit

scenic musk Jul 30, 2023, 4:30 PM

#

thats not how u would do it i think

#

here read this super nerdy forum post i read

#

https://devforum.roblox.com/t/using-fastcast-to-check-a-shots-validity/1272653/11

Developer Forum | Roblox

Using fastcast to check a shots validity?

Unfortunately fastcast doesn’t support immediate raycasting but we can achieve that ourselves by raycasting in segments along the projectile motions equation. I’m assuming the fastcast bullet is client sided with a remote telling the server “Hey I fired” and a remote telling the server “Hey this bullet I fired hit” and the system uses a bullet ...

#

now

#

if u go to the very end the creator of fastcast goes on to tell u to not do it on the client

#

timid breach Jul 30, 2023, 4:32 PM

#

yeah i saw it too

#

geromgwekll;p[l[pPOA,POAL,;AL;PFEWOPRE,OGER

scenic musk Jul 30, 2023, 4:33 PM

#

i think ur best bet might just be wht i said

#

then again i dont know whats better

#

having multiple casts going on

#

or having to reset the orientation everyframe

timid breach Jul 30, 2023, 4:33 PM

#

scenic musk ```lua lastRotation = 0 --We need to do this since the client owns the tank, it...

first im just gonna retry this hardcode fix

scenic musk Jul 30, 2023, 4:33 PM

#

on the server for multiple tanks

#

yeah try that

#

regardless more tanks u have the worse it'll get

timid breach Jul 30, 2023, 4:34 PM

#

wait

#

nvm i dont think this will work

scenic musk Jul 30, 2023, 4:34 PM

#

the fix i said?

timid breach Jul 30, 2023, 4:34 PM

#

scenic musk ```lua lastRotation = 0 --We need to do this since the client owns the tank, it...

this

scenic musk Jul 30, 2023, 4:34 PM

#

why not

timid breach Jul 30, 2023, 4:35 PM

#

because server changes rotation almost same speed as client does

#

which is a problem i think

#

or im not sure

scenic musk Jul 30, 2023, 4:35 PM

#

thats a good thing

#

u want the server and client to be in sync ideally

#

not sure what u mean

timid breach Jul 30, 2023, 4:35 PM

#

visually its going to jitter a lot

#

for the gunner

#

or not?

scenic musk Jul 30, 2023, 4:36 PM

#

ummm

#

not for the gunner

#

but for everyone else

#

well

timid breach Jul 30, 2023, 4:36 PM

#

wait

scenic musk Jul 30, 2023, 4:36 PM

#

yeah

timid breach Jul 30, 2023, 4:36 PM

#

i think there is one way

#

ACTUALLY

#

u know

#

steel titans

#

right

#

or not

scenic musk Jul 30, 2023, 4:36 PM

#

i know teen titans

#

not steel

timid breach Jul 30, 2023, 4:36 PM

#

lol

#

well um

#

these guys

#

a

#

yes

#

these guys

#

on the server

#

a

#

wait

#

um

#

OK sorry im losing my iq

#

they changed the turret rotation at a much slower speed On the server than in the clients

scenic musk Jul 30, 2023, 4:37 PM

#

its ok arent we all

#

thats what i said too

#

u use a click rotation system

#

that way it doesnt really matter

#

because u slowly rotate in the server

#

OH ALSO

#

because these tanks look rusty as hell

#

it might add to realism

#

hey

#

thats a bonus aint it

#

if its jittery good fo ru

timid breach Jul 30, 2023, 4:38 PM

#

wait wdym rusty as hell

scenic musk Jul 30, 2023, 4:38 PM

#

bro its a ww2 tank

#

no way it rotates perfectly

#

it has a little bit of stuck and rust

timid breach Jul 30, 2023, 4:39 PM

#

i mean its gonna teleport around in a stable speed

#

on the server

#

i think

scenic musk Jul 30, 2023, 4:39 PM

#

try it out and tell me what it ends up as

timid breach Jul 30, 2023, 4:39 PM

#

yes not now tho im gonna take a break

scenic musk Jul 30, 2023, 4:39 PM

#

ofc if it works i expect u to go around telling people ici helped u

timid breach Jul 30, 2023, 4:39 PM

#

yes

#

of course

scenic musk Jul 30, 2023, 4:39 PM

#

and when they ask u who is ici u tell them me

timid breach Jul 30, 2023, 4:39 PM

#

u can get

#

credit

scenic musk Jul 30, 2023, 4:40 PM

#

if it does not work

#

u stil tell them it was me

#

once it works

timid breach Jul 30, 2023, 4:40 PM

#

if u want u can join my server and if game gets famous (totally realistic scenario) u can be in special thanks or idk what uwant

scenic musk Jul 30, 2023, 4:40 PM

#

well

#

sure man why not

timid breach Jul 30, 2023, 4:40 PM

#

https://discord.gg/uFxTFC7p

tall dew Jul 30, 2023, 6:02 PM

#

Hi, I would like to check out your tank game also. I will join

timid breach Jul 30, 2023, 7:53 PM

#

@scenic musk hi you there?

timid breach Jul 30, 2023, 8:10 PM

#

okkkkkk the bug has been fixed

#

i removed the hitbox it was worst idea ever

#

instead the server gets the turret orientation every 0.25 seconds now so the client is updating the rotation faster than the server does, so for the gunner's perspective it's gonna be as smooth as possible

#

and not every heartbeat otherwise the gunner controls will be way too sloppy

scenic musk Jul 31, 2023, 3:45 AM

#

timid breach instead the server gets the turret orientation every 0.25 seconds now so the cli...

how do u do this?

#Tank game: Issue with Fastcast hit detection, and weld manipulation