# Sandbox.CameraEffectSystem.BaseEffect.Evaluate

```csharp
void Evaluate(float scale, ref Vector3 position, ref Angles angles, ref float fieldOfView)
```

Accumulate this effect's contribution. `position` is camera-local -
[Vector3.Forward](/api/Vector3/Forward) pushes the view forward, [Vector3.Up](/api/Vector3/Up) up.

### Parameters

- `scale` (`float`)
- `ref position` (`Vector3`)
- `ref angles` (`Angles`)
- `ref fieldOfView` (`float`)

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