1. Motion Capture: Serkis wore a motion capture suit with sensors attached to his body and face. This allowed the filmmakers to capture his movements and facial expressions in great detail.
2. Computer Animation: The digital model of Gollum was created using computer animation software. The animators used the motion capture data to create fluid and realistic movements for Gollum.
3. Andy Serkis' Performance: Serkis not only provided the motion capture data, but he also voiced the character and played a crucial role in shaping Gollum's personality and mannerisms. His emotional performance brought depth and complexity to the character.
The combination of these techniques resulted in a believable and visually stunning portrayal of Gollum that made him one of the most iconic characters in the Lord of the Rings film series.