Have you watched 3D-animated Disney flicks like Big Hero 6 and wondered how some of its scenes manage to look surprisingly realistic? Today's your lucky day: Disney has posted a top-level explanation of how its image rendering engine, Hyperion, works its movie magic. The software revolves around "path tracing," an advanced ray tracing technique that calculates light's path as it bounces off objects in a scene. It takes into account materials (like Baymax's translucent skin), and saves valuable time by bundling light rays that are headed in the same direction -- important when Hyperion is tracking millions of rays at once. The technology is efficient enough that animators don't have to 'cheat' when drawing very large scenes, like BH6's picturesque views of San Fransokyo. Although Disney's tech still isn't perfectly true to life, it's close enough that the studio might just fool you in those moments when it strives for absolute accuracy.