Timers & Delays

Need something to happen later, or on a repeating schedule? Here's how to handle time-based logic in HELIX.

One-Shot Delays

Run code after a specified delay:

Blueprint

Blueprint— One-Shot TimerScroll to zoom · Drag to pan · Drag nodes to move

Lua

-- Using the Timer API
Timer.SetTimeout(function()
    print("This runs after 3 seconds")
end, 3000)

-- Using UE's built-in timer
UE.UKismetSystemLibrary.K2_SetTimerDelegate(
    { self, self.OnDelayComplete }, 3.0, false
)

JavaScript

// Using standard JavaScript timers
setTimeout(() => {
    console.log("This runs after 3 seconds");
}, 3000);

// Or use async/await for sequential delays
function delay(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

async function countdown() {
    console.log("3...");
    await delay(1000);
    console.log("2...");
    await delay(1000);
    console.log("1...");
    await delay(1000);
    console.log("Go!");
}

Repeating Timers

Run code on a regular interval:

Blueprint

Blueprint— Repeating TimerScroll to zoom · Drag to pan · Drag nodes to move

Use Clear Timer by Handle with the return value from Set Timer by Event to stop a repeating timer.

Lua

-- Repeating timer (returns a handle for cancellation)
local handle = Timer.SetInterval(function()
    print("Tick! Current time: " .. os.clock())
end, 1000)

-- Stop the timer later
Timer.ClearInterval(handle)

JavaScript

// Repeating timer
const handle = setInterval(() => {
    console.log("Tick!", Date.now());
}, 1000);

// Stop the timer later
clearInterval(handle);

Coroutines in Lua

Lua coroutines let you write sequential-looking code that pauses and resumes across frames:

function M:ReceiveBeginPlay()
    -- Start a coroutine
    self.SpawnRoutine = coroutine.create(function()
        for i = 1, 5 do
            self:SpawnEnemy(i)
            print("Spawned enemy " .. i .. ", waiting...")
            coroutine.yield()  -- pause until resumed
        end
        print("All enemies spawned!")
    end)

    -- Resume it every 2 seconds
    self.TimerHandle = Timer.SetInterval(function()
        if coroutine.status(self.SpawnRoutine) ~= "dead" then
            coroutine.resume(self.SpawnRoutine)
        else
            Timer.ClearInterval(self.TimerHandle)
        end
    end, 2000)
end

Promises in JavaScript

For complex async flows, use Promises or async/await:

function delay(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}

function waitForPlayers(minPlayers) {
    return new Promise((resolve) => {
        const handle = setInterval(() => {
            // Check connected players (example — adjust to your game logic)
            const count = getConnectedPlayerCount();
            if (count >= minPlayers) {
                clearInterval(handle);
                resolve(count);
            }
        }, 500);
    });
}

async function startGame() {
    console.log("Waiting for players...");
    const count = await waitForPlayers(4);
    console.log(`${count} players ready. Starting!`);

    await delay(3000);  // 3 second countdown
    Helix.emit("GameStarted");
}

Tips

• Timer values in the Lua Timer API use milliseconds (1000 = 1 second). UE's built-in timer nodes use seconds.
• Always store timer handles and clear them when your actor is destroyed. Orphaned timers cause bugs that are tough to track down.
• Avoid running heavy logic on fast intervals (< 100ms). If you need per-frame updates, use Tick / ReceiveTick instead.
• The Blueprint Delay node is convenient but pauses that entire execution thread. For multiple independent delays, use separate timer handles.