Joaquin Phoenix, Amy Adams and Olivia Wilde Salute Spike Jonze at ‘Her’ Premiere

It was a full house at the Directors Guild of America on Thursday night for the Los Angeles premiere of Spike Jonze‘s Her.

Stars Amy Adams, Rooney Mara, Olivia Wilde and Joaquin Phoenix, who earned a Golden Globe nomination for his role, were among the cast that braved the brisk December evening air to support their director.

“It was Spike that drew me to this role — Spike sat down and he had such a great point of view, I think anyone who talked with him was on board,” Adams said. “He executed it beautifully.”

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Her is set in Los Angeles in the near future and follows Theodore (Phoenix), a sentimental divorcé who makes a living writing personal letters for other people. After separating from his wife (Mara), Theodore initially forms a friendship with “Samantha,” a female voice (Scarlett Johansson) that is part of an advanced operating system, but the two eventually fall in love. Adams plays the role of Amy, Theodore’s filmmaker neighbor who also develops a relationship with her OS.

The film explores society’s relationship with technology, questioning how far the interaction and intimacy should go.

“I think the [relationship] is going to go a lot further,” Johnny Knoxville, a collaborator with Jonze on the Jackass franchise and Bad Grandpa, told The Hollywood Reporter. “It’s going to get really ridiculous.”

Wilde, who is currently expecting, plays a single woman also struggling with loneliness and insecurity. “[Spike and I] talked a lot about what insecurity makes you hear when people speak to you, and the difference between what people may have said and what you may hear,” Wilde said. Actress Greta Gerwig attended in support of Wilde; both actresses participated in THR’s Breakthrough Performers Panel.

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“Spike sets up an environment on set that is unusual in that it feels very organic — the moments we are trying to create artificially are sort of created by the environment itself,” Wilde continued. “Working with someone like Joaquin is an unusual experience because he’s special. He has a very focused approach. He is so connected to the character that it feels seamless.”

Both Wilde and Mara shared that a large majority of their acting with Phoenix was improvised, and that Jonze encouraged a variation of approaches to the same scenes.

“I don’t think there’s a message behind this film; there isn’t anything specific that Spike wanted people to take out of it,” Mara said. “It’s a personal experience watching it, and there’s lots of different things you can take out of it.”

Her opens in select theaters on Dec. 18, 2013.