Very little is known about Terrence Malick's upcoming film -- except that Natalie Portman looks hot in it!

The 31-year-old actress showed off her amazing bod on set Tuesday in Austin, Texas. Portman, who is mom to son Aleph, 16 months, flaunted her flat tummy in a pink crop top shirt and short denim skirt.

PHOTOS: Natalie's gorgeous pregnancy

The Oscar-winning actress filmed scenes alongside Michael Fassbender, 35, for Malick's currently untitled project, reportedly set in Austin's music scene about two intersecting love triangles.

PHOTOS: Drastic hair makeovers in Hollywood

For her role, Portman, who is married to dancer-choreographer Benjamin Millepied, got a makeover to go from brunette to blonde. "Natalie makes a beautiful blonde!" colorist Tracie Cunningham told Us Weekly. "She needed to make the change for an upcoming movie role, and using Redken's Blonde Dimensions we achieved a gorgeous, multi-dimensional golden blonde."

PHOTOS: Natalie's romance history

The film is also set to star Ryan Gosling, Rooney Mara, Christian Bale and Cate Blanchett. And it looks like Gosling, 31, and Mara, 27, will also have a romance in the film. On Sept. 25, the young Hollywood stars were photographed shooting a kissing scene!

This article originally appeared on PIC: Blonde Natalie Portman Shows Off Flat Tummy, Legs in Skimpy Outfit