20 things you didn't know about the making of 'Star Wars: The Last Jedi'

Warning: There are some spoilers ahead if you have not seen "Star Wars: The Last Jedi."

Now that "Star Wars: The Last Jedi" is out in theaters, books that Disney has been heavily guarding to prevent spoilers have also been released.

While we won't get the film's tie-in novelization until March, if you're looking for some more details on "The Last Jedi," you should consider reading "The Art of Star Wars: The Last Jedi."

The book takes a deep dive into the concept art and ideas that went into the four-plus years of making the sequel. It also contains interviews with director Rian Johnson, concept artists, costume designers, and others who worked on the movie.

While we still have a lot of questions after seeing the latest installment of "Star Wars," the book helps shed light on some of the early inspiration for "The Last Jedi."

Keep reading to see what we learned about the making of the movie.

Rey could have interacted with Luke's old X-wing ship.

One early idea was for Rey to stumble upon Luke's old X-wing in the caves on Ahch-To.

"Rey explores the island, trying to understand Luke's self-imposed exile from the universe. She comes across a cave, sunk at high tide within the base of the island," wrote visual effects art director Kevin Jenkins. "Here she discovers Luke's scuttled T-65 X-wing, rusted and rotting away in the water. It was set alight before it sank. It shows Luke's commitment to his exile, as he destroyed his only means of leaving the planet."

Instead, director Rian Johnson went with designs similar to Skywalker's sunken ship painted by artist Doug Chiang in 2013 off the island's coast. 

Luke Skywalker's character was inspired by Marlon Brando in "Apocalypse Now."

Colonel Kurtz (Brando) is the antagonist of the 1979 movie who goes rogue and is believed to have gone insane. Luke has some parallels to the decorated war officer in "The Last Jedi," in which he's a tortured man cut off from the rest of the world. However, the Master Jedi is able to find peace by the film's end.

The porgs were inspired by the puffins on Skellig-Michael where island scenes were filmed.

Ultimately, the porgs were a combination of a few animals.

"We'd explored ideas that drew from birds, bats, flying squirrels, and aquatic creatures such as seals, otters, and beavers," said creature concept designer Lunt Davies. "The influences for the design were a seal combined with a pup dog. At this stage they had seal-like fur, flippers for wings, and webbed feet. They were flightless and would be more at home underwater, like penguins."