# PhysicsConstants

> Constants used throughout the 2D physics system.

## Definition

* **Type:** Struct
* **Namespace:** [Unity.U2D.Physics](/engine/7000.0/script-reference/unity/u2d/physics.md)
* **Assembly:** UnityEngine.PhysicsCore2DModule
* **Implements:** [IEquatable\<PhysicsConstants>](https://learn.microsoft.com/dotnet/api/system.iequatable-1)

```csharp
public readonly struct PhysicsConstants : IEquatable<PhysicsConstants>
```

## Static Fields

| Value                                                                                                                | Description                                                                                                                                                                                                                                                      |
| -------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [MaxBounceIterations](/engine/7000.0/script-reference/unity/u2d/physics/physicsconstants/maxbounceiterations.md)     | The maximum number of bounce passes a physics world can run in one simulation step.                                                                                                                                                                              |
| [MaxPolygonVertices](/engine/7000.0/script-reference/unity/u2d/physics/physicsconstants/maxpolygonvertices.md)       | The maximum number of supported vertices in [PolygonGeometry](/engine/7000.0/script-reference/unity/u2d/physics/polygongeometry.md).                                                                                                                             |
| [MaxWorkers](/engine/7000.0/script-reference/unity/u2d/physics/physicsconstants/maxworkers.md)                       | A constant defining the maximum number of worker threads supported by physics simulation. The current device may support fewer or more than this.                                                                                                                |
| [MaxWorldCapacity](/engine/7000.0/script-reference/unity/u2d/physics/physicsconstants/maxworldcapacity.md)           | The maximum number of [PhysicsWorld](/engine/7000.0/script-reference/unity/u2d/physics/physicsworld.md) that can exist at one time. The world array grows on demand up to this ceiling, which is the limit of the 16-bit world index carried in physics handles. |
| [MaxWorldNameLength](/engine/7000.0/script-reference/unity/u2d/physics/physicsconstants/maxworldnamelength.md)       | The maximum length of a [PhysicsWorld](/engine/7000.0/script-reference/unity/u2d/physics/physicsworld.md) name, beyond which [PhysicsWorld.SetName](/engine/7000.0/script-reference/unity/u2d/physics/physicsworld/setname.md) truncates it.                     |
| [MinMaximumLinearSpeed](/engine/7000.0/script-reference/unity/u2d/physics/physicsconstants/minmaximumlinearspeed.md) | The lowest maximum linear speed a physics world accepts, in meters per second. A world limited to this speed lets bodies move no more than a tenth of a millimeter each second, so it behaves as if nothing can move.                                            |