Is Gollum in the movie "Lord of the Rings" played by a real person?

Specifically, it is CG technology, and more specifically, it is CG+ motion capture technology. An actor equipped with dynamic capture dots (usually small white dots) performs the actions of Glenn (also translated as Gollum) in front of a blue screen (or green screen), and the capture camera captures the movements of the small white dots. That is, the actions of the actor. After that, CG technology is used to attach skin to the action and add light and shadow effects. Finally, it was synthesized into the movie.

This requires a very expensive graphics workstation, which is not a job that ordinary PCs can handle