# useSubStepContacts

> Whether to calculate contacts for all simulation sub-steps or only the first sub-step.

## Definition

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

```csharp
public static bool useSubStepContacts { get; set; }
```

### Remarks

When simulation sub-stepping is enabled with [Physics2D.useSubStepping](/engine/6000.0/script-reference/unityengine/physics2d/usesubstepping.md), this property is used to control the whether or not contacts are calculated for all sub-steps or only the first sub-step.

When enabled, contacts are calculated for all sub-steps. This provides a more accurate simulation for each sub-step but will reduce performance. In most cases, this extra contact calculation isn't required.

When disabled, contacts are only calculated for the first sub-step. Subsequent sub-steps only perform integration and constraint solving. This increases performance whilst still maintaining a stable simulation. In most cases, this should be used.

Additional Resources: [Physics2D.useSubStepping](/engine/6000.0/script-reference/unityengine/physics2d/usesubstepping.md), [Physics2D.minSubStepFPS](/engine/6000.0/script-reference/unityengine/physics2d/minsubstepfps.md), [Physics2D.maxSubStepCount](/engine/6000.0/script-reference/unityengine/physics2d/maxsubstepcount.md), [PhysicsScene2D.subStepCount](/engine/6000.0/script-reference/unityengine/physicsscene2d/substepcount.md) and [PhysicsScene2D.subStepLostTime](/engine/6000.0/script-reference/unityengine/physicsscene2d/substeplosttime.md).