# SimulationMode2D

> A selection of modes that control when Unity executes the 2D physics simulation.

## Definition

* **Type:** Enum
* **Namespace:** [UnityEngine](/engine/6000.0/script-reference/unityengine.md)
* **Assembly:** UnityEngine.Physics2DModule

```csharp
public enum SimulationMode2D
```

## Remarks

Additional Resources: [Physics2D.simulationMode](/engine/6000.0/script-reference/unityengine/physics2d/simulationmode.md).

## Fields

| Value                                                                                      | Description                                                                                                                                                                                                           |
| ------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [FixedUpdate](/engine/6000.0/script-reference/unityengine/simulationmode2d/fixedupdate.md) | Use this enumeration to specify to Unity that it should execute the physics simulation immediately after the [MonoBehaviour.FixedUpdate()](/engine/6000.0/script-reference/unityengine/monobehaviour/fixedupdate.md). |
| [Script](/engine/6000.0/script-reference/unityengine/simulationmode2d/script.md)           | Use this enumeration to specify to Unity that it should execute the physics simulation manually when you call [Physics2D.Simulate](/engine/6000.0/script-reference/unityengine/physics2d/simulate.md).                |
| [Update](/engine/6000.0/script-reference/unityengine/simulationmode2d/update.md)           | Use this enumeration to specify to Unity that it should execute the physics simulation immediately after [MonoBehaviour.Update()](/engine/6000.0/script-reference/unityengine/monobehaviour/update.md).               |