Scale
The Classic Animation faction of Warner Bros., which animated the commercials and was located in Sherman Oaks, Los Angeles, was originally planned to be the only company responsible for Space Jam. However, after only a week, the animation work was so complicated that Warner Bros. contacted more studios, including reassigning the Feature Animation division in Glendale from working on Quest for Camelot (1998) to Space Jam. Ten of Classic Animation's members, including the production's animation director Tony Cervone, were taken out of the faction to become involved all throughout production, and development artists were reassigned to animating jobs, including supervising animator Bruce Woodside, who had little faith in the project: "Like so many other animators, I adore the classic Warner Bros. characters, but I really had little hope that tying them to the massive anchor of an apparently doomed marketing scheme could actually give them a successful second life in features." Other animators and artists working on the film included Chuck Gammage, Darren Vanderburg, Dave Spafford, Hiram Maxem, Mark Swan, Gary Dunn, Denis Couchon, Neil Boyle, Kirk Tingblad, Pepe Valencia, Tom McGrath, Fraser MacLean, Jacques Muller, Ashanti Miller, and Uli Meyer.
After Cervone was hired as animation director, Jerry Rees contacted Bruce W. Smith about being another animation director on the film; Rees was fired by the time Smith joined, and Pytka hired Smith to direct the animation sequences alongside Cervone. Before January 1996, when animation production was put into overdrive, none of the animators' drafts or concepts for how the film should look met with Reitman's approval; Bill Perkins joined that month as animation art director, and when first arriving at the Sherman Oaks division, "we only had around eight months to do about 52 minutes of animation" and "it was just kind of a little skeleton crew." Cervone highlighted Reitman's role as supervisor: "It started off as a string of gags with no structure, and he helped a lot with that." The drafting process involved the animators and artists using the original cartoons as references. Ultimately, they went with Bob Clampett's style of animation due to being wilder than Chuck Jones' style.
Tingblad storyboarded the scene in which Sniffles gets squashed by the Monstar Blanko, out of dislike for the character. Cervone stated, "I remember people at that time going, 'No one even knows who Sniffles is.' [But] we remember Sniffles. We've been waiting to hit Sniffles with a basketball for many years… And I do think that might be one of the reasons we're still talking about it is the movie does seem like it has this raw energy to it, chaotic energy to it in an off-kilter structure."
Production of Space Jam totaled around 19 months, with filming taking up ten of them; this was half the time of any other film of its kind according to Smith. The animation was done at a very
quick pace by more than 700 workers from 18 studios in London, Canada, California and Ohio, starting January 1996 by the recently joined producers Ron Tippe and Allison Abbate. In trying to track the huge amount work done at the 18 studios, Tippe hung stills of all the shots throughout the Feature Animation faction's hallways, with completed ones marked in red.
Features about the film's production, including one from the official website, emphasized its state-of-the art computer technology when it came to its live-action/animation hybrid; "this film could have not been made two years ago," claimed Cervone in 1996. Due to its mixture of various art mediums as well as the "broad sense of humor and entertainment" unique to Looney Tunes, Smith considered Space Jam an important part of diversifying the animation industry. The film broke the record for amount of composited shots in a featured film, "roughly 1,043" according to Tippe, as well as a record number of FX shots, with around 1,100 in a single 90-minute film; Independence Day (1996), released the same year, had 700 FX shots within two hours of screen time. Tippe claimed the film would have, at most, "multiple characters, multiple levels of effects and, in some cases, up to 70 elements" in one shot.