Home, the buddy comedy from DreamWorks Animation about an alien invasion, was born in West Philadelphia.

Set for release on Friday, the computer-animated family film is based on The True Meaning of Smekday, an uproarious children's novel penned by writer and illustrator Adam Rex. For eight years, Rex and his wife lived in West Philadelphia while she earned her Ph.D. in physics from the University of Pennsylvania.

In Smekday, a West Philly girl, voiced in the movie by Rihanna, embarks on a roadtrip to search for her mother who has been abducted by an inept race of aliens. Along the way, she meets up with an on-the-lam outcast (The Big Bang Theory's Jim Parsons in Home) who is hiding from his fellow intersteller invaders.

(Steve Martin and Jennifer Lopez also lend their vocal talents to the film.)

We spoke recently with the impish Rex about the genesis of Smekday, his work as an in-demand illustrator, and his thoughts on the movie-making process.

Was there an item on the Adam Rex bucket list that read: Write a post-apocalyptic novel about an alien invasion, a Philly girl and her alien BFF?

 Adam Rex: Back in 2001 I was reading a lot of world history, and you can't read world history without it coming off like a litany of all the terrible things people can do to each other. It made me remember who I was when I was 12. I'm a European-American, and at that time I identified with historical European-Americans, and as a result I didn't always empathize with the right people.

So as an adult I wondered what could have made the 12-year-old me feel kinship with the colonized rather than the colonizers, and an alien invasion story seemed like a way to do that.

So my story could have gotten really dull and didactic; luckily it turned out more like a Hope-Crosby road movie with explosions and just a subtext of all that allegory.

Steve Martin, Rihanna, Jim Parsons, Jennifer Lopez. Discuss.

This just seems to be a list of names. Is it a puzzle? If I anagram them I get "A tinnier harvestman rejoins frozen nipple jams."

Were you surprised when Smekday was picked up by Dreamworks and became a 3D movie with characters voiced by A-list cast?

No. It was my debut novel, and like most debut novels it had a contract rider that specified I get a big-budget movie and Steve Martin.

Philadelphia plays a bit part in Smekday (and makes for a beautiful image on the front of the book jacket). What did you do while you were here? Has the city made any other appearances in your work?

I worked out of my home from cafes like The Green Line. Is that still there? It's hard to account for all you did over the course of eight years, but I remember a lot of eating. Philly and its suburbs are the setting of my young adult novel Fat Vampire, and it pops up in my Cold Cereal Saga as well – a trilogy that's partially set in sort of a mystical alternate-reality Camden.

You're one of the few writers who can illustrate as well as they can tell a tale. Though the art in Smekday is mostly in comic strip form, the illustrations in your Frankenstein books are exquisitely rendered paintings. Who do you consider your main influences/predecessors? Who are your favorite artists and storytellers?

In terms of novel writing, I've been influenced a lot by people like Douglas Adams and Neil Gaiman and Kelly Link. I seem to read Breakfast at Tiffany's about once a year just to marvel at how perfect it is. I also think I got into children's books in the first place mostly because of Jon Scieszka and Lane Smith.

I love painters like Phil Hale, John Singer Sargent, N.C. Wyeth, Kent Williams. Illustrators like Christian Robinson, Carson Ellis, Isabelle Arsenault.

You have six novels under your belt and two volumes of monster-themed poetry. You also appear to be in high demand for your book illustrations and images for fantasy role-playing games. What do you consider your best work? And what do you find most satisfying?

I haven't done any work for fantasy role playing games for something like ten years, but that is where I got my start as an illustrator. I consider The Cold Cereal Saga to be some of my best storytelling, and those three books haven't garnered quite the same readership as Smekday.

What made you decide to write for kids?

I like kid's books. I like to tell stories in both word and image, so it was this or comics or both. And kids are just a good match for the kinds of stories I want to write — they're more willing to follow a story into unfamiliar territory than a lot of adults would be.

In the True Meaning of Smekday, Gratuity's alien friend is named "J.Lo." Were you disappointed when the filmmakers redubbed him "Oh?"

Yeah, if I'm honest I'd say that and the title change were the biggest emotional hurdles for me. I dealt with those emotional hurdles the same way I dealt with real hurdles back in freshman P.E.: I got a note from my doctor and I sat on the bleachers that week.

Where did the names for "Smek" and the alien race "the Boov" come from?

Boov is a homophone for the nickname of one of my wife's former physics colleagues at Penn: Bhuvnesh. I never asked him permission and he's having a weird year because of it. I think Smek just sounded good. I knew I wanted our alien conquerors to rename all our holidays, so the title The True Meaning of ____Day came to me early on. It wasn't always Smek. But Smek's predecessor turned out to be a swear word in England, so I changed it.

Were you involved with adapting the book for film?

Not much. The team that was working on Home had me out to DreamWorks a number of times to look at designs and watch unfinished screenings. It was clear that they really wanted me to like what they were doing, and they asked for notes. Eventually they even asked me to write a little new material when they were punching things up. They weren't under any obligation to listen to my notes or use any of that material, though, and in the end they mostly did their own thing, which I think is as it should be.

How is the movie? Are you happy with it?

Oh yes.

Smek for President, the sequel to the True Meaning of Smekday was just released. Has the studio expressed any interest in a second film?

It's DreamWorks's M.O. to make sequels of films that do well enough to justify them, so the answer to this is "Yes, but." We'll see. They certainly won't be able to adapt Smek for President directly because of the changes they made to my first story in Home. But I do hope they'll be able to use some of it.

The illustrations you did for The Dirty Cowboy by Amy Timberlake caused the book to be banned in two school districts, one in Texas and another here in Pennsylvania. That puts you in the select company of authors such as Mark Twain, J.K. Rowling, and Toni Morrison whose books have also been ejected from school libraries. Were you surprised at the strong reactions the book generated?

It does put me in good company, but it also puts me in a lot of middling-to-bad company. I understand the instinct to want to treat a banning like a badge of honor, but I don't feel that way about it personally. I like and respect kids and want to make good books for them, and some people in at least two states have decided that something I made is bad for children. For me there's just no getting around being hurt by that.I was surprised at the reaction, but I don't know that I'll be so surprised when it happens again. Outrage has become something like a fifth food group in our culture, so it's only a matter of time.

What's your next project?

It's bad P.R. to say it's a secret, but a secret is what it is.

Contact Sam Wood at 215-854-2796 or samwood@phillynews.com. Follow @samwoodiii on Twitter.