Park pilot, "Cartman Gets an Anal Probe", did not do well with test audiences, and Comedy Central executives were unsure whether they wanted to order any additional episodes. However, they paid Parker and Stone to write another script when Internet buzz began to generate about the duo and their work on The Spirit of Christmas, the 1995 animated short film that served as a precursor to South Park. The network opted not to commit to a full Comedy Central series until they could read the newly commissioned script. The result was "Weight Gain 4000", which the two South Park creators wrote while they were working on their 1997 comedy-action film, Orgazmo. In writing the script, the duo sought to give Comedy Central executives an idea of what the series would be like and how each show could differ from the others. Parker and Stone also said they would not write another script until the network signed off on the full show with a season of at least six episodes. Comedy Central liked the script and agreed to commit to a series. While "Cartman Gets an Anal Probe" was created almost entirely with construction paper, "Weight Gain 4000" was the first South Park episode made completely using computers. It was created in little over a month in a studio in Westwood, California, by about 15 animators using PowerAnimator, the Alias Systems Corporation animation program most commonly known as "Alias", which would be used in subsequent episodes. In the future, South Park shows would be created within a week of their broadcast dates and require about 40 animators. "Weight Gain 4000" was animated in chronological order from beginning to end. Although Parker and Stone sought to improve the details and textures of the characters and overall animation, they also specifically chose Alias because it would allow the animation to maintain the deliberately crude visual style they first created with construction paper in The Spirit of Christmas and "Cartman Gets an Anal Probe". The South Park creators and animators said they were still developing the characters and trying to figure out the future direction of the show with "Weight Gain 4000", which was more slow-paced than the series would eventually become. The 30-page script was shorter than in later episodes, which would average between 45 to 50 pages. The child protagonists also spoke slower. While recording their voice performances, the actors read the