# FixedUpdate

> Use this enumeration to instruct Unity to execute the physics simulation immediately after the MonoBehaviour.FixedUpdate().

## Definition

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

```csharp
FixedUpdate = 0
```

### Remarks

Executing the physics simulation during [MonoBehaviour.FixedUpdate()](/engine/6000.0/script-reference/unityengine/monobehaviour/fixedupdate.md) provides the most stable physics simulation, however Unity might render multiple frames between simulation updates. This might prevent synchronization of changes made per frame, including contacts between [Collider](/engine/6000.0/script-reference/unityengine/collider.md)s, with the physics simulation. This mode requires [Rigidbody](/engine/6000.0/script-reference/unityengine/rigidbody.md) interpolation to provide smoother movement per frame where appropriate.

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