The studio also developed several new tools to generate realistic and believable shots, particularly the heavy and deep snow and its interactions with the characters. Disney wanted an "all-encompassing" and organic tool to provide snow effects but not require switching between different methods. As noted above, several Disney artists and special effects personnel traveled to Wyoming to experience walking through deep snow. Dr. Kenneth Libbrecht, a professor from the California Institute of Technology, was invited to give lectures to the effects group on how snow and ice form, and why snowflakes are unique. Using this knowledge, the effects group created a snowflake generator that allowed them to randomly create 2,000 unique snowflake shapes for the film.
