The Butterfly Effect is a complex short movie rendered in realtime (Direct3D 11) via the Unity 4 engine:
The Butterfly Effect is a collaborative project between Unity Technologies Stockholm office, two-time Academy Award winning creators of Gorillaz visuals Passion Pictures, and Nvidia to push Unity to new levels of technological advancement. The goal, through the creation of a high-quality real-time rendered short, was to take many techniques and workflows used to create hollywood blockbusters and apply them to Unity in ways that would benefit the entire Unity community.
More information here: The Butterfly Effect
Source: Geeks3D forum