Walt Disney Imagineers Unveil NVIDIA-Powered Olaf Robot

Walt Disney Imagineering has unexpectedly given Frozen’s lovable snowman Olaf a very lifelike pair of legs that look and function like the actual thing. This new Olaf robot roams the crowds at Hong Kong Disneyland, engaging with children and waving to visitors in a way that makes him appear to have sprung straight out of Arendelle. It took years for the engineers to transform a collection of code and motors into something that truly feels alive, and the ultimate result is right in the heart of the park’s new World of Frozen.

Engineers created Olaf from scratch to preserve the movie’ quirky appeal. His body is comprised of a soft, squishy material that moves with each step, not just his feet, but the entire body. Even the most expensive plastic cannot roll in the same manner those snowball legs can. His eyes dart about to lock onto faces, his mouth opens wide for laughter, and the carrot nose comes flying off if you tug hard enough. And all the while, he’s confidently balancing on his own two feet, avoiding strollers, and high-fiving hands, none of which are dependent on a rail or track. The crew drew on lessons from earlier robots, such as the droids who guard the Star Wars regions, but they really pushed the envelope to make Olaf’s waddle feel unique, as if he had his own personality. They examined the animators’ sketches for every twitch and movement.

Olaf’s brain is built around deep reinforcement learning. This method allows the robot to practice walking and waving until it gets it just right, all from within a computer before it ever steps foot on the floor. They plugged in some movie clips, made some tweaks, and modified until the motions were identical, right down to the way he sashays in his hips. So no more stiff poses or jerky starts; Olaf simply glides along, pauses to throw a brief check over his shoulder, and then picks up speed as if he’s late for a real snowball fight. And with 20 degrees of movement in his arms alone, as well as sensors that map the environment around him in real time, you can be sure he won’t be knocked off balance anytime soon. Of course, one false move in a crowded park may spell tragedy, but the software learns from each close call and adjusts his path on the fly to keep him upright.

NVIDIA jumped in early to provide graphics power to accelerate the simulations. Without powerful computers, training a robot like this would take months; with them, the team conducts parallel experiments, stacking variations until one sticks. Google DeepMind contributed their expertise in machine learning to help create Newton, a tool that anybody can use and build on. Kamino, the simulator within, solves the complex arithmetic for bodies as floppy as Olaf’s, reducing what used to take weeks to days. Bruce Vaughn, Imagineering’s creative director, describes it as a subtle revolution in which the technology fades into the background and the story takes control.

Guests in Hong Kong get a first taste at limited events in the Frozen zone. Olaf appears for discussions that take minutes, not seconds, quoting lines from movies or riffing on the weather. When a child asks about summer, he shouts out a song; when a family poses for photos, he leans in with a smile. In Disneyland Paris, the identical setup awaits him in their World of Frozen, where he will participate in shows and stroll the bay. For the time being, the numbers are minimal, with only one or two units per place, but the pace rises up quickly. Imagineering is already planning new characters, ranging from playful sidekicks to towering creatures, to walk freely by next year.