LOS ANGELES — When Tupac Shakur rose from the stage in the California desert earlier this year, it was not only a jaw-dropping resurrection, but also the beginning of a new form of live entertainment.
''Come with me,'' the digital Shakur called out, not just to tens of thousands of screaming fans but seemingly to other artists.
Follow, they will. Elvis Presley's estate announced it has authorized holograms of the King of Rock, Marilyn Monroe's estate has expressed interest, and there's no shortage of other beloved stars whose fans would die to see them perform again.
Advances in digital artistry make it all possible, presenting celebrity estates with new commercial and creative opportunities, but also some ethical quandaries.
''I think we've scratched the surface with Tupac,'' said Dylan Brown, a filmmaker who along with director Philip Atwell and effects studio Digital Domain helped bring the Shakur hologram to life. ''If it's done tastefully, like Tupac was done tastefully, I think it could be a wonderful form of entertainment.''
Brown, owner of The Yard Entertainment, and Atwell, owner of Geronimo Films, had each toyed with the idea of using holograms in concerts for a decade, but the technology wasn't there. Brown, who works closely with Snoop Dogg and Atwell, who collaborates with Dr. Dre, knew that once they chose Shakur for the holographic debut, it had to be more than just a technological marvel.
''We wanted to be really respectful of the family foremost,'' said Atwell. ''We just wanted to do something that wasn't in bad taste.''
Reaction to the Shakur hologram at the Coachella Valley Music and Arts Festival was huge, with the performance garnering 15 million YouTube hits within 48 hours and winning a top award at the creative marketing gathering Cannes Lions.
''You start to open up a whole new universe of legal questions,'' said Ed Ulbrich, chief creative officer of Digital Domain, which is also working on the Presley holograms. ''As such, we have no intentions of doing anything other than being utterly respectful of these legends and icons.''
Because it's two-dimensional, the Shakur performer isn't a true hologram, which, by definition, is a 3-D image (Ulbrich notes the technology isn't quite there for that). But it's a vivid digital creation that audiences are far more accustomed to seeing in movies — except there is no screen.
Brown and Atwell say part of the challenge was integrating Shakur's performance into the larger show featuring Snoop Dogg, Dr. Dre, and others.
Shakur's entry and exit had to be carefully planned to fit into the show, with the creators opting to have his image burst apart into a cloud of gold specks. Brown and Atwell said the dissolve seemed most appropriate. ''He has a mystique and that aura that kind of transcends death, even,'' Brown said.
Stars wield extensive control over how their names, voices, and images are used after they die through likeness, trademark, and copyright protections, and now holograms offer them yet another consideration.
Before digital filmmaking, attorney Laura Zwicker said the question for her clients boiled down to ''Could you use my photograph?'' Now they have to consider whether they'll be returned to the big screen, inserted in commercials, or put back onstage, said Zwicker, a strategic wealth planner in the LA office of the firm Greenberg Glusker.
Celebrity likeness rights vary around the country, with stars' estates in California enjoying 70 years of protection. Indiana offers 100 years, and 16 other states have laws protecting celebrities' likenesses, said Jeremiah Reynolds, an attorney with the firm Kinsella Weitzman Iser Kump and Aldisert. The firm handles numerous intellectual property issues, including those related to Michael Jackson's estate.
While holograms are likely covered by existing laws, potential legal challenges will likely focus on whether the performance is protected by the First Amendment. ''You get into very subjective areas about what is artistic,'' Reynolds said.
Courts have been divided about whether a work featuring a celebrity — or one closely based on a star — is transformative and warrants its own protection, or infringement, Reynolds said.
''You get into very subjective areas about what is artistic.''
Marilyn Monroe's estate threatened legal action earlier this year against a company claiming it was working on a digital show using the model-actress's likeness. The technology for holograms or other digital performances is intriguing, the estate's handlers at Authentic Brands say, but they would only partner with people who could make a top-notch product.
Brown and Atwell said they felt enormous pressure to make sure the Shakur performance was worthy of being an introduction to a new form of live entertainment.
''I also hope that the people who do follow us do it with the same care and the same sense of dedication because I would hate to see a bad version of Marilyn Monroe, a bad version of Elvis up there,'' Brown said.
Brown and Atwell are proud that Shakur is leading the hologram revolution.
''We're part of the hip-hop generation,'' Brown said. ''It shows the growth of that culture, of that business and it says a lot about what we've dedicated part of our lives to.''
''There was a time, 15 years ago, 20 years ago, when people were waiting for hip-hop to disappear,'' he said. ''Now not only is hip-hop here to stay, even if you die we'll bring you back.''