Hardware Sensors Required for ARKit 2 on iOS 12

Running ARKit 2 applications on iOS 12 requires a specific combination of hardware sensors and processing hardware capable of real-time Visual-Inertial Odometry (VIO). This article outlines the essential built-in sensors—primarily the camera, motion sensors, and ambient light sensors—as well as optional hardware like the TrueDepth camera system necessary for the advanced augmented reality capabilities introduced in ARKit 2.

Camera System

A high-resolution rear camera is mandatory for standard ARKit 2 experiences. ARKit utilizes the camera feed for visual tracking, surface detection, 2D image recognition, and 3D object scanning. The camera continuously captures real-world imagery, identifying high-contrast visual feature points in the physical space to anchor digital content accurately.

Inertial Measurement Unit (IMU)

ARKit relies heavily on sensor fusion to calculate device movement. The device's internal IMU consists of:

  • Accelerometer: Measures linear acceleration to detect movement speed, direction, and spatial translation.
  • Gyroscope: Measures angular velocity and orientation changes, allowing ARKit to monitor device rotation, tilt, and pitch across six degrees of freedom (6DoF).

By combining data from the camera and the IMU, ARKit’s Visual-Inertial Odometry provides low-latency, accurate tracking even during rapid device movements.

Ambient Light Sensor

The ambient light sensor monitors the surrounding environmental illumination. ARKit 2 uses this sensor data to estimate real-world lighting conditions, dynamically applying realistic shadows, reflections, and color temperatures to 3D virtual objects to ensure they blend seamlessly into the real world.

TrueDepth Camera System (Feature-Specific)

While the rear-facing setup is sufficient for world-tracking experiences, the front-facing TrueDepth camera system is required for ARKit 2's advanced face tracking and facial expression capture. This system includes:

  • Infrared Camera
  • Dot Projector
  • Flood Illuminator

The TrueDepth setup captures detailed 3D mesh representations of human faces and enables gaze and eye tracking, which were introduced in ARKit 2 on devices such as the iPhone X and newer.

Processor Requirement (Sensor Fusion)

Sensors alone are insufficient without the computing capability to process high-throughput data streams simultaneously. ARKit 2 requires an Apple A9, A10, A11, or A12 Bionic chip (or newer). These processors contain the necessary CPU, GPU, and Neural Engine hardware to handle real-time computer vision algorithms and sensor fusion without inducing significant latency.