Lag Compensation¶

Lag compensation for hitboxes is usually done with a table of player movement snapshots so you can rewind and view where a player was at. Chrono timestamps server snapshots using the server's os.clock while forwarding the client's clock for interpolation. This allows lag compensation to be done easily.

How?¶

Client¶

When firing a hitbox event, send workspace:GetServerTimeNow():

local clientServerTimeNow = workspace:GetServerTimeNow()
Hitbox:FireServer(targetPlayer, clientServerTimeNow)

Server¶

To use it for hit validation, receive the time, then rewind.

local Entity = require(chrono.Shared.Entity)
local Holder = require(chrono.Shared.Holder)

Hitbox.OnServerEvent:Connect(function(attacker: Player, target: Player, clientServerTimeNow: number)
    local latency = workspace:GetServerTimeNow() - clientServerTimeNow
    local rewindTo = os.clock() - latency
    --you can also account for interpolation delay as well but you must send it from the client and then clamp it 
    --should also be validating the timestamps against something like Getnetworkping to prevent exploiters from spoofing it.
    local attackerWasAt = Entity.GetAt(Holder.GetEntityFromPlayer(attacker), rewindTo)
    local targetWasAt = Entity.GetAt(Holder.GetEntityFromPlayer(target), rewindTo)
end)