Fresh off the success of Snow White and the Seven Dwarfs in the late 1930s, Walt Disney knew he needed to deliver something even more spectacular for his sophomore animated feature. How he got there—the trials and tribulations, the character and story development, the innovative new techniques and more—is the basis for Wish Upon a Star: The Art of Pinocchio, an exhibit that opens today at the Walt Disney Family Museum in San Francisco.

Curated by Academy Award-winning animator John Canemaker, the exhibit features more than 300 objects that provide a glimpse into how much effort it took—and how challenging it was—to bring the story to life.

"Walt halted production on the film in June 1938 for about six months to fix problems with the story, which was adapted from a rambling newspaper serial that started in 1881 and ran for three years and 36 chapters," Canemaker tells mental_floss. That included problems with the main character, who, in the original serial, was depicted as "a cruel, selfish brat, a wooden puppet with little audience appeal." Not exactly Disney material.

So how did animators arrive at the friendly little marionette people have known and loved for decades? That's part of what visitors to the exhibit will learn when they view early storyboards and character designs for Pinocchio and his pals. "By making him more sympathetic, Disney profoundly affected the story and the audience’s perceptions, and made Pinocchio a star," Canemaker says.

The Walt Disney Family Museum

The exhibit also shows the evolution of techniques and effects that began with Snow White. "The special effects animation is amazing, both hand-drawn and mechanical, specifically the use of the multiplane camera, which lent a three-dimensional quality to scenes," Canemaker explains. "The device was used much more extensively in Pinocchio than in Snow White. The stunning tracking shot of Pinocchio’s village waking up and kids going to school is one of the greatest multiplane camera scenes in animation history—and one of the most expensive!"

The Walt Disney Family Museum

From comparing flipbooks of the animators's drawings to the finished products, to listening to the Oscar-winning score and viewing documentary clips from the original creators, Canemaker selected objects to make Wish Upon a Star immersive and interactive.

"What surprised me personally as a curator was how much original artwork survives from this 76-year-old film," Canemaker says. "We have over 300 artworks in the exhibit—drawings, cels, backgrounds, animator’s drawings, storyboards, concept sketches, layout drawings, photographs. And wait until you step into a section called Geppetto’s Workshop with its 3D character maquettes that were used for reference by the animators. Wonderful stuff!"

The Walt Disney Family Museum

Though the movie may be more than 75 years old, it still resonates with audiences, and that, Canemaker says, is no coincidence. “There has never been anything like it before, or since. It hits all the buttons: adventure, warmth, spectacle, and emotional storytelling. It is a fascinating world that envelops you from the get-go, when a tiny cricket dressed in a tuxedo sits atop a large book singing about making wishes come true.”

The exhibit will be featured at the Walt Disney Family Museum in San Francisco from May 18, 2016 through January 9, 2017.