One of the most publicized features of the iPhone X is the Animoji, an ingenious feature that allows users to map their facial movements in an emoji to say short messages. The function is only available on the iPhone X, as it incorporates the True Depth facial detection system.
A few days ago, the well-known YouTuber Marques Brownlee said that, according to his tests, the functionality does not require the use of TrueDepth. This means that, if Apple wanted, it could make the Animoji work on older iPhones.
Animoji Depth Technology of iPhone X
However, this information does not seem to be accurate: Apple uses information from the True Depth camera to help track the facial movements of Animoji. We emphasize the word help because this is not the only source of information used, but the front camera plays a fundamental role in the process.
Can Animoji work without TrueDepth? Yes, but with worse quality in facial tracking, which can translate into small interruptions of Animoji movements. In his initial video, Marques Brownlee explained that he has spoken with Apple about the Animoji and that the company has explained that they use infrared data and depth sensors for greater accuracy. On an iPhone without these sensors, the Animoji experience would be inferior.
Animoji uses the TrueDepth infrared system on the iPhone X to periodically update a depth map but also uses the front camera constantly to track facial movement and expressions. There is a logical explanation for why Animoji may seem to work even when you cover the True Depth camera: the Apple True Depth camera does not perform a continuous 3D reading. Instead, take measurements at fixed intervals. When you cover the sensor, the system may simply use the latest 3D map.
The first depth reading is performed when the user starts Animoji. Therefore, if you cover the infrared system – the left side of the notch – before starting Animoji, the performance degrades. The difference is best appreciated with Snapchat. The app incorporates filters for the face that take advantage of True Depth on the iPhone X to make a much better facial tracking. If you cover the True Depth sensors, the old tracking system is used, which is worse.