While Pixar Animation Studios is celebrating a milestone with the release of its 10th feature film in "Up," the studio still remains high on one of its earlier achievements: a project so important that, without it, a movie like "Up" -- or its seven predecessors, for that matter -- would have never gotten off the ground.

Appropriately, the groundbreaking movie is the ant-filled "A Bug's Life," which has just made its debut on Blu-ray and been re-released as a deluxe edition DVD (Walt Disney Home Entertainment). The film's pioneering director, Jon Lasseter, considers "A Bug's Life" one of the most important -- if not the most important films Pixar has ever produced -- even over "Toy Story," which earned him a special achievement Oscar.

"The difference between the release of 'Toy Story' and 'A Bug's Life' is night and day," Lasseter said in a recent @ The Movies interview. "It takes four years to produce each of our movies and from 1991 to 1994, when we were making 'Toy Story,' no one knew we even existed. But when it came out, it was like 'Butch Cassidy and the Sundance Kid.' Everyone was saying 'Who are those guys?'"

Suddenly, Lasseter said, Pixar not only had a blockbuster movie, but a successful IPO led by Pixar's then-CEO, Steve Jobs. Not only was the public awaiting what Pixar would produce next: so were the stockholders.

"It felt like were making 'A Bug's Life' in a fishbowl," Lasseter recalled. "Everybody was excited about it and saying, 'It better be good.' There was an awful lot of pressure. So we just stepped back, got the same group together that made 'Toy Story' and said, 'OK. Let's just make a good movie.'"

Released in 1998, "A Bug's Life" tells the adventure of Flik (voiced by Dave Foley), a misfit ant who recruits a group of oddball bugs from a flea circus to help save the ant colony from a group of evil grasshoppers, led by cruel Hopper (Kevin Spacey). The movie's characters and setting were decidedly different than "Toy Story's," which made the project all the more challenging, Lasseter said.

"'Toy Story' was the perfect first movie to make because pretty much everything in the toy world is geometric," Lasseter said. "But when we got into the insect world, it's a world of nature: everything is organic. It's organic in its shape and the way it moves. The level of complexity in 'A Bug's Life' was so much bigger than 'Toy Story.'"

One advantage Lasseter said to making "A Bug's Life" was that the creative team didn't have to go far to do research.

"A lot of people get to go out to exotic countries to do their research -- we did ours by sticking our heads underneath the planters in front of Pixar," Lasseter mused. "Our tech guys built what we called a 'bug's camp' so we could see things from the point-of-view of an insect. We noticed everything in the entire world at that level is translucent -- every glass blade, every petal and every leaf. It's like living in a world where you're looking out a stained-glass window."

Lasseter is obviously excited to share his view of "A Bug's Life" again with movielovers on DVD, but perhaps more so in that it's finally being presented in the best home presentation possible with Blu-ray.

"I watched my first Blu-ray with 'Cars' at home and decided, 'There's no going back.' I'm such of a fanatic about because of the picture quality and the sound," Lasseter said. "What I also love about it is that there is so much space on the disc, so we can do a lot more features for it. At Pixar we've been such fanatics about quality on home video, that way back on 'Toy Story,' we did a deluxe Laserdisc because we were all Laserdisc collectors and fans of the features and the commentary.

"Now that Blu-ray has come along, I'm just thinking about all of the possibilities of what we can do," Lasseter added. "At Pixar we like to say that we over-deliver. Not only do you get a movie that looks and sounds great, but all of this extra stuff."