# Sandbox.ModelBuilder.AddCollisionBox

```csharp
ModelBuilder AddCollisionBox(Vector3 extents, System.Nullable<Vector3> center = null, System.Nullable<Rotation> rotation = null)
```

### Parameters

- `extents` (`Vector3`)
- `center` (`System.Nullable<Vector3>`), default `null`
- `rotation` (`System.Nullable<Rotation>`), default `null`

### Returns

`ModelBuilder`

Declared in [Sandbox.ModelBuilder](/api/Sandbox.ModelBuilder).
Assembly: `Sandbox.Engine`.