Meet Olaf: The Frozen Robot Poised to Transform Disney Parks

You know Olaf. Before the K-Pop Demon Hunters and the Wicked movies took the stage, Disney’s Frozen introduced us to unforgettable show tunes like “Let It Go” and “Into the Unknown.” My daughters loved belting those songs out.

So, when I encountered Olaf, the Disney Imagineering robot, I couldn’t help but think about how excited my kids would be to meet him too. It’s a strange thought, considering this Olaf isn’t a “he” in the traditional sense and can’t hold a conversation. Yet, I keep saying “I met him” because he’s essentially a remote-controlled puppet operated by a Steam Deck gaming handheld.

Olaf is set to make his debut at Disneyland Paris on March 26th and at Hong Kong Disneyland this summer. He’s one of those rare robots that successfully crosses the uncanny valley, especially when he’s in motion. This is thanks to Disney animators who trained him by creating 100,000 virtual versions of the physical Olaf robot in a Nvidia-powered simulation, rewarding him for movements that match the screen character. It only took two days to train Olaf using an Nvidia RTX 4090 GPU.

“This is definitely the future of how we’re creating robot characters,” says Disney Imagineering’s SVP of R&D, Kyle Laughlin. He believes that reinforcement learning is the key to populating entire areas with interactive characters, allowing for the construction of robots in months rather than years. While Disney has previously done similar work with Star Wars droids, Laughlin notes, “This is our first animated character that we brought to life.”

To clarify, Olaf is not equipped with artificial intelligence. Standing 35 inches tall and weighing 33 pounds, this robot features 25 actuators and three computers, including an Nvidia Jetson Orin NX and a Raspberry Pi, but it doesn’t generate its own speech. Instead, it plays pre-recorded lines from Olaf’s voice actor, Josh Gad, while performing animated movements.

While Olaf can blink on his own, he can’t “see” you to engage directly; that requires the operator to use a joystick. The other joystick on the Steam Deck directs Olaf’s movement, and the operator can swipe across a touchpad to access various conversation options. During my demo, the interaction felt limited, often resulting in quick responses like “Of course!” or “Sure!”

But when Olaf is in motion, it’s hard to look away, and I find myself referring to him as “him” repeatedly. His waddling is so convincing! Disney Research lab director Moritz Bächer explains why: “The eyes go first, and the body follows.” We instinctively perceive him as a living being because the eyes are so engaging.

Olaf’s costume, made from a four-way stretch material over foam “snowballs,” sparkles like fresh snow in the light. His carrot nose, stick arms, and buttons are magnetic, allowing for easy reattachment or playful detachment.

While Disney is known for safeguarding its intellectual property, it approaches its robot research differently. Last March, it collaborated with Nvidia and Google DeepMind to release the Newton Physics Engine as an open-source project managed by the Linux Foundation. Now, Disney Research is also contributing Kamino, a simulation tool designed to train complex mechanical assemblies like Olaf and future robots, including a thermal dynamics model to prevent overheating joints.

Olaf presented unique challenges, particularly due to his large head resting on a small neck, which puts strain on that joint and can lead to overheating. His clomp-clomp-clomp walking also posed a noisy problem. However, in the reinforcement learning simulation, Disney rewarded the 100,000 virtual Olafs that managed to move without overheating or making excessive noise. “It’s like telling my six-year-old to stop running through the house: Can you just be a little bit quieter? That’s pretty much what we had to do for Olaf,” Laughlin explains.

Bächer mentions that these tools are designed to work with existing animator software like Maya, allowing animators to create motions that convey emotions while the physics simulation handles the practicalities of what the bots can actually do.

I have to admit, the illusion falters when Olaf stops moving, and Disney Research hasn’t indicated when these robots might achieve true autonomy. It seems that the technology isn’t quite up to Disney’s standards yet. Bächer states that “believable autonomy” is the goal: “It needs to be something that you believe is real.”

However, Olaf won’t always be controlled by a human with a Steam Deck. He can also be part of time-coded performances, integrated directly into Disney’s live entertainment choreography systems. Laughlin notes that this is one of the first ways he’ll appear at Disneyland Paris, performing on a boat in a lagoon in front of the castle. “We built a mock boat in our R&D lab to simulate the considerable amount of rocking back and forth, and Olaf does an incredible job staying afloat,” he says. “He’s got his sea legs.”

As Disney continues to develop more robots, Laughlin suggests that performances may become even more captivating. “You can expect to see more robots from franchises together so that they can interact.”

“The real power will come from Olaf interacting with characters he knows and loves. Not just performers, but also other characters we haven’t been able to bring to life without robotics,” he hints.

Disney Research has published an eight-page white paper detailing how Olaf was created, including some of the specific components and formulas used.