Development
The idea for a series about a boy with super-genius powers was first conceived in the 1980s by John A. Davis, who scripted and storyboarded a short narrative titled Runaway Rocketboy, centering around a character named Johnny Quasar (inspired by a facetious nickname that his summer co-workers had coined for him in his youth) who builds a rocket ship and runs away from his parents. Davis stated in an episode of the Nickelodeon Animation Podcast that he initially wrote the concept with the intention of creating it as a live-action film with special effects and matte shots, even going so far as to apply for a grant to fund the project, but found that getting such an investment was difficult since the film was not educational or informative. The idea laid dormant for several years until Davis came across the abandoned script while in the process of moving. Around the same time, Davis' Dallas-based studio, DNA Productions, had just begun experimenting with the use of computer animation after obtaining copies of LightWave 3D. In turn, Davis realized that the film would be fitting as a CGI film, since all of the science fiction set pieces could be entirely modeled in 3-D.
Davis, alongside studio co-founder Keith Alcorn, created a 40-second proof-of-concept demo film which depicted Johnny and his robot dog, Goddard, flying through an asteroid belt and greeting the viewers. Simultaneously, Davis and Alcorn worked to create a story bible outlining a potential television series. The demo short was shown off in 1995 at the SIGGRAPH CGI convention, where it was entered into a competition for LightWave films. The demo quickly garnered notability in the computer animation industry, receiving frequent press coverage in magazines and winning two "Wavey" awards- one for Best Character Animation and another for Best in Show. Among people who caught wind of the film was Steve Oedekerk, the founder of O Entertainment, who saw a still shot of Johnny and Goddard in a CGI magazine. Oedekerk, a strong backer of computer animation, was impressed by the characters' designs, stating in an interview that the image particularly stood out to him because it "seemed fun" compared to the mostly-photorealistic work being done with computer animation at the time. He cold-called Davis requesting to see a tape of the full short. After watching the demo, as well as seeing the show bible which Davis and Alcorn had developed, Oedekerk expressed interest in helping to pitch their concept to different networks.
After teaming up with O Entertainment, the company began working on developing a full-length episode for a TV series, titled The Adventures of Johnny Quasar, writing an expanded version of the original Runaway Rocket story and tweaking aspects of Johnny's design to make him look more like a child. In Fall 1995, the idea was pitched to Nickelodeon, who expressed immediate interest in the idea. Albie Hecht, the then-president of Nick, was particularly impressed, coining him to be "half Bart Simpson and half Albert Einstein", he strongly praised Johnny's blended personality as an adventurous and intelligent character and one grounded in the reality of childhood, which, according to him, made him "the perfect Nick kid". Following positive reception, Nickelodeon commissioned for a 13-minute pilot episode to be created. After several years of going through the review process, the episode began production in late 1997, and was completed in 1998. The name "Johnny Quasar" was changed at the request of Nickelodeon, who did not want the character to be confused with similarly named ones such as Jonny Quest and Captain Quazar, so Davis brainstormed other character names while walking his dog around the neighborhood block, eventually coming up with the final name, "Jimmy Neutron".
After the pilot was completed, Nickelodeon executives, who were impressed by the pilot and still enthusiastic about the show's potential, raised the prospect of creating a theatrical film to accompany the TV series, much to the surprise of Davis and his team at the studio. During the initial pitch to Nickelodeon, Oedekerk had highlighted the idea that using computer animation would allow the same models and assets to be reused between both a film and a TV show, an idea which Nick held strong faith in. Davis further suggested that the feature film be created first, since the characters being modeled could be created at a higher quality than they would have with a TV budget. Although Nick was worried that it would be more difficult to attract a movie-going audience without the TV show to build an install base for the series, these concerns were answered with a series of short TV interstitials which would begin airing in order to build up hype for the upcoming film.
With a budget of roughly $30 million, production of Jimmy Neutron: Boy Genius was greenlit in Fall 1999, and work began on a script for the film. Production officially started in February 2000 under the direction of Davis. In order to speed up the pace of work for a feature film, the company's staff count was considerably increased from 30 to around 150 employees, and the studio's workspace was also reformed in order to fit such a team of filmmakers. The film was completed in 24 months, roughly half that in which most other CGI films were completed.