AR Technology

This topic explains the technical process behind Augmented Reality. Understanding these steps helps you follow later development topics with ease.

Step 1: Capture the Real World

A camera on the device records live video of the surrounding area. This video acts as the base layer that digital content sits on top of.

Step 2: Detect Surfaces and Features

Software scans the video for flat surfaces, edges, and recognizable patterns. A table, floor, or wall becomes a surface the app can place objects on. This process is called surface detection.

Step 3: Track Position in Real Time

The device tracks its own movement using cameras and motion sensors together. This combined method is called visual-inertial odometry. It lets the app know exactly how far and which direction the device has moved since the app started.

Step 4: Render and Overlay Digital Content

Once the app knows the surfaces and the device position, it draws a digital object in the correct spot and size. The object appears to stay fixed in place even as the user walks around it.

Diagram: AR Processing Pipeline

Marker-Based vs Markerless AR

Marker-based AR uses a printed image or QR code as a fixed reference point. The app recognizes the marker and places content directly above it. Markerless AR skips the printed marker and instead scans the environment directly, which gives users more freedom to place objects anywhere.

Simple Example

Picture a museum app that scans a printed poster and plays a video above it. That app uses marker-based AR. Now picture a furniture app that lets you place a virtual sofa anywhere on your living room floor without any printed image. That app uses markerless AR.

Why This Process Matters

Every AR app you build later in this course relies on these four steps. A clear grasp of capture, detection, tracking, and rendering makes debugging and designing new AR features far easier.