fps affecting physics

[tacit oyster]

i am trying to make a game and when i put my fps to 240 it works perfectly, but the lower the fps i set it to, the worse it gets (insanely fast acceleration and weird turning) does anyone know how to help or if theres anyway to fix it, ill put the script in the chat if anyone wants to look

[remote grove]

ts is probably cause you use RunService

it runs per frame

[tacit oyster]

yeah i do idk what else to use

[south gate]

** You are now Level 3! **

[remote grove]

ig dont use runservice?

[tacit oyster]

and replace with what

[remote grove]

task.spawn(function()
    while task.wait() do
        --code
    end
end)

maybe with sum like that

[tacit oyster]

ok i will try

[echo iris]

Are you using DT from the RunService function?

[tacit oyster]

local now = os.clock()
local dt = math.clamp(now - last, 0, 1/20)
last = now

i got this

[echo iris]

RunService already has a parameter for DT, you don't need to calculate it yourself

[tacit oyster]

oh

[echo iris]

RunService.Stepped:Connect(function(dt) end)

[tacit oyster]

RunService.Heartbeat:Connect(function(dt)

i got this now but it still weird

it accelerates like 2x speed

[echo iris]

Well how are you using DT?

It's in seconds, mostly less than a second (unless things are really laggy)

[tacit oyster]

do u wanna see my full runservice

[echo iris]

Maybe just one instance of you using DT for something like speed rather than all of your code

[tacit oyster]

local fwd = speedForward
local df  = targetFwd - fwd
if math.abs(throttle) < 0.05 then
    fwd = fwd * math.max(0, 1 - (DECEL_COAST * dt) / math.max(1, MAX_SPEED))
else
    local accel = (math.sign(targetFwd) ~= math.sign(fwd) and BRAKE_POWER or ACCEL_FWD) * ctrlMult
    if boostMul > 1 then accel *= BOOST_ACCEL_MUL end
    fwd = fwd + math.clamp(df, -accel * dt, accel * dt)
end
fwd = math.clamp(fwd, -speedCap, speedCap)

i forgot how u do that lua thing with the `

[hollow wren]

```lua
```

[tacit oyster]

-- hi

oh ok

[hollow wren]

oh god, I've only just noticed that you both have df and dt... that's why I got confused

[tacit oyster]

bro this code is a mess idk what im doing

[hollow wren]

I would just slowly note down all the math you're doing and just then check what needs to get a time influence. Right now I can see a lot of things getting multiplied by dt in clamps and such, but if you don't ever actually do that in the applying then it's useless

Also, a quick note:

fdw = fdw + ...
fdw = fwd * ...
*= and += exist, it will already help with readability

[echo iris]

I would suggest naming things more clearly

[tacit oyster]

oh yeah ok thanks

[tacit oyster]

ok

[tacit oyster]

yeah its not very clear rn

[remote grove]

https://www.youtube.com/watch?v=-J3wNP6u5YU