"Final Fantasy X" features innovations in the rendering of characters' facial expressions, achieved through motion capture and skeletal animation technology. This technology allowed animators to create realistic lip movements, which were then programmed to match the speech of the game's voice actors. Nojima has revealed that the inclusion of voice acting enabled him to express emotion more powerfully than before, and he was therefore able to keep the storyline simple. He also said that the presence of voice actors led him to make various changes to the script, in order to match the voice actors' personalities with the characters they were portraying. Despite being worried about the inclusion of voice acting, Nomura was satisfied when hearing their clip as he stated the characters "became full of life." The voice acting brought difficulties in the making of the English version of the game as the localization team has to translate Japanese dialogues into English-oriented lines as well as fit the characters' lip movements.