---
title: eventWaveformUseVolumeEnvelope
framework: corehaptics
role: symbol
role_heading: Type Property
path: corehaptics/chhapticpattern/key/eventwaveformusevolumeenvelope
---

# eventWaveformUseVolumeEnvelope

A key that identifies whether audio file playback fades in and out using an envelope.

## Declaration

```swift
static let eventWaveformUseVolumeEnvelope: CHHapticPattern.Key
```

## See Also

### Haptic Pattern Keys

- [event](corehaptics/chhapticpattern/key/event.md)
- [eventDuration](corehaptics/chhapticpattern/key/eventduration.md)
- [eventParameters](corehaptics/chhapticpattern/key/eventparameters.md)
- [eventType](corehaptics/chhapticpattern/key/eventtype.md)
- [eventWaveformLoopEnabled](corehaptics/chhapticpattern/key/eventwaveformloopenabled.md)
- [eventWaveformPath](corehaptics/chhapticpattern/key/eventwaveformpath.md)
- [parameter](corehaptics/chhapticpattern/key/parameter.md)
- [parameterCurve](corehaptics/chhapticpattern/key/parametercurve.md)
- [parameterCurveControlPoints](corehaptics/chhapticpattern/key/parametercurvecontrolpoints.md)
- [parameterID](corehaptics/chhapticpattern/key/parameterid.md)
- [parameterValue](corehaptics/chhapticpattern/key/parametervalue.md)
- [pattern](corehaptics/chhapticpattern/key/pattern.md)
- [time](corehaptics/chhapticpattern/key/time.md)
- [version](corehaptics/chhapticpattern/key/version.md)