Article

Tracking the Force of 3D Touch Events

Manipulate your content based on the force of touches.

Overview

A touch on the screen primarily conveys the location of that touch. However, devices that support 3D Touch also report the amount of force imparted by the user’s finger onto the screen. (Similarly, Apple Pencil reports the amount of force at its tip to the connected device.) You can use both the touch location and the force value as input to your app. For example, a drawing app might use force to set the thickness of the current line.

Figure 1

Using force as input

An illustration of how 3D Touch devices can detect touch force. A finger is shown pressing on the display, with rings emanating outward to indicate a force touch.

The raw force value associated with a touch is available in the force property of the UITouch object. You can compare that value against the value in the maximumPossibleForce property to determine the relative amount of force.

For guidance about using 3D Touch, see iOS Human Interface Guidelines.

Topics

Related Articles

Checking the Availability of 3D Touch

Check whether a device supports 3D Touch before enabling features that use it.

See Also

Touches

Handling Touches in Your View

Use touch events directly on a view subclass if touch handling is intricately linked to the view's content.

Handling Input from Apple Pencil

Learn how to detect and respond to touches from Apple Pencil.

Leveraging Touch Input for Drawing Apps

Capture touches as a series of strokes and render them efficiently on a drawing canvas.

UITouch

An object representing the location, size, movement, and force of a touch occurring on the screen.