Coachella’s Tupac was a 2-D creation of Digital Domain Media Group, who won a visual effects Oscar for aging Brad Pitt in The Curious Case of Benjamin Button. And it was projected using technology dating from the 19th Century:
The effect relies on an angled piece of glass in which a “ghostly” image is reflected. “A piece of glass can be both transparent and reflective at the same time, depending on how it’s situated relative to the audience,” said Mr. Steinmeyer, pointing out the secret.
In the Victorian version of the trick, the glass reflected an actual actor, situated out of sight in near the orchestra. On Sunday night, the image was projected on a piece of Mylar—a highly reflective, lightweight plastic—stretched on a clear frame.
A similar effect was used in 2003 to project an image of Frank Sinatra. Virtual Tupac may go on tour later this year with other (living) hip-hop stars