The BindToRenderStep() function binds a custom function to be called at a specific time during the render step. There are three main arguments: name, priority, and what function to call.

As it is linked to the client's rendering process, BindToRenderStep() can only be called on the client.

Name

The name parameter is a label for the binding and can be used with RunService:UnbindFromRenderStep() if the binding is no longer needed.

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local RunService = game:GetService("RunService")

local function functionToBind() end

-- Bind the function above to the binding named "tempBinding"
RunService:BindToRenderStep("tempBinding", 1, functionToBind)
-- Unbind the function bound to "tempBinding"
RunService:UnbindFromRenderStep("tempBinding")

Priority

The priority of the binding is an integer; it determines when during the render step to call the custom function. The lower this number, the sooner the custom function will be called. If two bindings have the same priority, the Roblox Engine will randomly pick one to run first. The default Roblox control scripts run with these specific priorities:

• Player Input: 100
• Camera Controls: 200 For convenience; the RenderPriority enum can be used to determine the integer value to set a binding. For example, to make a binding right before the default camera update, simply subtract 1 from the camera priority level.

When using RenderPriority, remember to use .Value at the end of the desired enum. RunService:BindToRenderStep() will not work if just the enum is used on its own.

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local RunService = game:GetService("RunService")

local function beforeCamera(delta)
	-- Code in here will run before the default Roblox camera script
end

RunService:BindToRenderStep("Before camera", Enum.RenderPriority.Camera.Value - 1, beforeCamera)

Custom Function and Delta Time

The last argument (function) is the custom function to call. This function will be passed one parameter called deltaTime which shows how much time passed between the beginning of the previous render step and the beginning of the current render step.

All rendering updates will wait until the code in the render step finishes. Make sure that any code called by BindToRenderStep() runs quickly and efficiently; if code takes too long, the experience visuals will be choppy.

The Heartbeat event fires every frame, after the physics simulation has completed. The deltaTime argument indicates the time that has elapsed since the previous frame.

This event is when most scripts run. It occurs at the end of each frame and it's also when any waiting scripts are executed, such as those scheduled with the task library. Heartbeat is commonly used for periodic tasks, such as updating core game systems like health regeneration.

Following this step, the engine sends property updates and events to the server or clients which are later received as part of the replication receive step.

If the code that invoked this method is running in a client context (in a LocalScript, in a ModuleScript required by a LocalScript, or in a Script with RunContext set to RunContext.Client), this method will return true. In all other cases, this method will return false.

If this method returns true, the current environment can access client‑only features like RunService.PreRender or Players.LocalPlayer.

This method returns whether the Run button has been pressed to run the simulation in Studio. It will continue to return true if the simulation has been paused using the Pause button; however, once it has been stopped using the Stop button, it will revert to returning false.

Note that Studio only enters "run" mode when the Run button is pressed, not the Play button. Also note that this method will return false if the simulation was started using RunService:Run() rather than the Run button.

Returns whether the experience is currently running, meaning the simulation has been run using the Run or Play buttons.

IsRunning() will always return the inverse of IsEdit() except when the simulation has been paused, in which case both methods will return false.

This method returns whether the current environment is running on the server. If the code that invoked this method is running in a server context (in a Script with RunContext set to RunContext.Server or RunContext.Legacy, or in a ModuleScript required by a Script), this method will return true. In all other cases, this method will return false.

If this function returns true, then the current environment can access server‑only features like ServerStorage or ServerScriptService.

This method returns whether the current environment is running in Studio. It can be used to wrap code that should only execute when testing in Studio.

The PostSimulation event fires every frame, after the physics simulation has completed. The deltaTimeSim argument indicates the time that the current frame has stepped the physics simulation, not accounting for physics throttling.

This event is useful for making final adjustments to the outcome of the simulation. Following this phase, the engine triggers the Heartbeat event.

The PreAnimation event fires every frame, prior to the physics simulation but after rendering. The deltaTimeSim argument indicates the time that the current frame has stepped animations.

This event is useful for modifying animation objects, such as adjusting their speed or priority. Once the PreAnimation event is complete, the engine proceeds to run these animations, updating the joint transforms which will later be used to update objects during the physics simulation.

After animations are stepped, the engine triggers the PreSimulation event.

The PreRender event (replacement for RenderStepped) fires every frame, prior to the frame being rendered. The deltaTimeRender argument indicates the time that has elapsed since the previous frame.

This event allows you to run code and update the world before it's drawn on a player's screen. This is useful for last‑minute adjustments such as changing object positions, updating animations, or preparing visual effects, but it should be used sparingly as the engine cannot start to render the frame until code running in this event has finished executing.

As PreRender is client-side, it can only be used in a LocalScript, in a ModuleScript required by a LocalScript, or in a Script with RunContext set to RunContext.Client.

Following the PreRender phase, the simulation phase begins with the PreAnimation event.

The PreSimulation event (replacement for Stepped) fires every frame, prior to the physics simulation. The deltaTimeSim argument indicates the time that the current frame will step the physics simulation, not accounting for physics throttling.

This event is useful for adjusting properties like velocity or forces just before they're applied as part of the simulation. The simulation then runs, potentially multiple times, as the physics solver runs at a higher frequency than other engine systems. Once this is complete, the PostSimulation event is fired.

Fires every frame, prior to the frame being rendered.

Migration Note

This event has been superseded by PreRender which should be used for new work.

Fires every frame, prior to the physics simulation.

Migration Note

This event has been superseded by PreSimulation which should be used for new work.

Given a name of a function sent to BindToRenderStep(), this method will unbind the function from being called during PreRender. This is used to unbind bound functions once they are no longer needed, or when they no longer need to fire every step.

If there is no bound function by the given name, this method takes no action and continues without raising an error.