Apple developer Noah Witherspoon declaredwhat’s in the new watch face”unity lights» Apple Watch uses ray tracing technology.
Ray tracing (ray tracing) is a rendering technique that uses the principles of real physical processes. In order to build a three-dimensional model of an object and apply ray tracing to it, the system traces the trajectory of a virtual ray to this object. In other words, lighting changes according to physical laws in real time.
In the Watch, Apple used technology to dynamically change the position of shadows. Thus, we see how the hands of the dial cast shadows in real time.
It is amazing that such a technology might be implemented in such a compact device.