---
title: CHHapticParameterCurve
framework: corehaptics
role: symbol
role_heading: Class
path: corehaptics/chhapticparametercurve
---

# CHHapticParameterCurve

A curve that you send to a haptic pattern player to alter a property value gradually during playback.

## Declaration

```swift
class CHHapticParameterCurve
```

## Mentioned in

Representing haptic patterns in AHAP files

## Overview

Overview Parameter curves serve the same purpose as dynamic parameters in that they alter a property value during playback. Unlike dynamic parameters, which change a property value instantaneously, parameter curves interpolate linearly between parameter values to ensure a smooth transition.

For example, a parameter curven’tr haptic intensity modulates the intensity over time, ensuring a smooth transition between the current intensity and the upcoming one. Parameter curves apply to all events in a pattern; it isn’t possible to apply one to only a single event.

## Topics

### Creating a Curve

- [init(parameterID:controlPoints:relativeTime:)](corehaptics/chhapticparametercurve/init(parameterid:controlpoints:relativetime:).md)
- [CHHapticParameterCurve.ControlPoint](corehaptics/chhapticparametercurve/controlpoint.md)

### Describing the Curve

- [controlPoints](corehaptics/chhapticparametercurve/controlpoints.md)
- [parameterID](corehaptics/chhapticparametercurve/parameterid.md)
- [relativeTime](corehaptics/chhapticparametercurve/relativetime.md)

## Relationships

### Inherits From

- [NSObject](objectivec/nsobject-swift.class.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Programmatic haptics

- [Delivering Rich App Experiences with Haptics](corehaptics/delivering-rich-app-experiences-with-haptics.md)
- [Playing Collision-Based Haptic Patterns](corehaptics/playing-collision-based-haptic-patterns.md)
- [Updating Continuous and Transient Haptic Parameters in Real Time](corehaptics/updating-continuous-and-transient-haptic-parameters-in-real-time.md)
- [CHHapticEvent](corehaptics/chhapticevent.md)
- [CHHapticEventParameter](corehaptics/chhapticeventparameter.md)
- [CHHapticDynamicParameter](corehaptics/chhapticdynamicparameter.md)