Tupac Shakur's posthumous appearance at this year's Coachella Festival has sparked interest in resurrecting other dead celebrities for live appearances, including Elvis Presley.

Digital Domain, the company that created the Tupac figure that performed alongside Snoop Dogg and Dr. Dre, is keen to use new technology to allow audiences to see more from deceased stars. However, critics have called the practice creepy.

What they have created with the Tupac appearance is not a hologram — as the public dubbed it — but a digital projection, says Digital Domain's chief creative officer Ed Ulbrich. 

The Los Angeles company, founded in 1993 by director James Cameron and two business partners, specializes in creating special effects for film. Effective technology that allows a digital projection of a human being is fairly recent, Ulbrich said, beginning with the projection of an 85-year-old Brad Pitt in The Curious Case of Benjamin Button.

"The vast majority of the response globally has  been positive," Ulbrich said in an interview with CBC's Q cultural affairs show, adding that the phone was ringing constantly the next day with people interested in the technology.

"Our objective is not to create virtual likenesses of deceased icons to sell cheese curds and sneakers. With Tupac, it was handled so elegantly and with such respect. It was a tribute to him. No one was making money off him...It was done with the blessing of Tupac's mother," Ulbrich said.

However, cultural critic Nathan Rabin, head writer of The Onion's entertainment section The A.V. Club, found the idea of recreations of both Tupac and Elvis "exploitive."

The projections are "disturbing and fascinating," he told Q's Jian Ghomeshi, but added that they risk ruining the legacy of the artist.

Dre and Tupac did not get along in Tupac's lifetime and it would be ridiculous to think they would perform together, Rabin said.

Since the rapper's shooting death in 1996, others — including his record label — have tried to profit from his music, according to Rabin. "He was a puppet of whoever wanted control and this is taking it to the next level."