Due to limitations in computer technology, especially regarding attempts to capture the complexity of a human form, many basic principles of animation used in traditionally animated movies had been absent from earlier CGI films; but technological advancements made it easier to blend the two, combining the strengths of each style. Keane stated repeatedly he was trying to make the computer "bend its knee to the artist" instead of having the computer dictate the artistic style and look of the film. By making the computer become as "pliable as the pencil", Keane's vision of a "three-dimensional drawing" seemed within reach, with the artist controlling the technology. Many of the techniques and tools that were required to give the film the quality Keane demanded did not exist when the project was started, and Walt Disney Animation Studios had to create them on their own. Keane said, "There’s no photoreal hair. I want luscious hair, and we are inventing new ways of doing that. I want to bring the warmth and intuitive feel of hand-drawn to CGI."