The aqua slapped onto the canvas first. Then white, cobalt and cotton candy pink. Yellow blurted on with a rude noise, followed by red and black. This was on a frigid morning in a borrowed art studio in the Sunset Park section of Brooklyn. In a crumbly brick building along the industrial waterfront, the actor Adrien Brody knelt on a drop cloth, smearing and swirling paint with a plastic card until it formed patterns, layers and streaks.

“Painting, I would say, was my first love,” he said.

Mr. Brody, 48, who won an Oscar nearly two decades ago for “The Pianist,” has recently returned to painting, having shown his work, somewhat reluctantly, he said, at Art Basel Miami Beach and at an art fair in New York. The child of artistic parents — his mother, Sylvia Plachy, is a photographer, and his father, Elliot Brody, is a painter — he grew up drawing and painting.

As a teenager, he had applied to the visual arts program at the Fiorello H. LaGuardia High School of Music & Art and Performing Arts. The arts program rejected his portfolio, but the drama department accepted him. The occasional graffiti tag aside, he gave up painting.

After a year at Stony Brook University and a semester at Queens College, he began acting in earnest, attracting the interest of Hollywood and art house directors including Terence Malick, Spike Lee, Barry Levinson, Ken Loach and Roman Polanski. While still in his 20s, he acquired a reputation as an actor of ferocious commitment and unstinting preparation, modifying his body when required, doing his own stunts when legal, eating a worm if a scene required it.

“I don’t set out to do things that are difficult,” he said. “That’s not really what I’m looking to do. But things are difficult. And things that are meaningful tend to be difficult. I don’t know the easy way.”

Eight or nine years ago, when rewarding roles were thinner, he found himself with a brush in his hand again. After a yearslong renovation of his castle in upstate New York near Syracuse, he invited his friend, the painter Georges Moquay, to create an original work for a central wall. Mr. Moquay suggested that Mr. Brody paint alongside him.

Mr. Brody painted a dragon. Mr. Moquay was impressed and asked why he wasn’t painting. Mr. Brody had no good answer. So he began again, taking inspiration from the graffiti of his New York City youth.

Since then, whenever he films on location, he carves out an artist studio in his temporary digs. “I’m compelled to keep producing,” he said.

That morning in Brooklyn, he had woken up early at his home in Westchester County. With the help of his girlfriend, Georgina Chapman, the Marchesa designer, he had packed up his materials — canvases, acrylics, pastel sticks, spray paints, brushes — and brought them to a studio borrowed from Bill Hickey, a street artist.

“It’s kind of recreating what I have it all strewn about,” he said, arranging his paint tubes.

Once he started working, the chitchat stopped. He produced a 3-foot-by-4-foot canvas with a skull that he had sketched in charcoal the night before, and spread paint around its edges, blotting it with bits of brown paper and distressing it with a paintbrush.

From a mini-fridge he grabbed a bottle of water. He uncapped it and took a gulp, before pouring a steady stream onto the canvas, jiggling it to make the paint run. He spray painted some spider web and labyrinth stencils, followed by blobs of gold, then poured water over those, too.

Mr. Brody worked fast and intuitively, stooping, crouching, kneeling and squinting his sad eyes. “I don’t know what I’m going to do,” he said. “I like to just do it.”

Paint stained his fingers, his shoes, his camouflage pants. A shoelace came untied. Several times he said that he had finished, but after pausing a few seconds, he would return to the canvas, daubing and smudging and spilling again. He didn’t know the easy way.

“I’ll let it dry, then I’ll come back,” he said. But he couldn’t leave it alone. Instead, he unwrapped a fresh charcoal stick and touched up the outline of the skull, edging each tooth. He used white paint to make the light parts lighter, then black paint to darken the rest. He poured water over that, too. Then he splattered the canvas with his black brush.

“This is the problem, you just can’t stop,” he said, more than an hour after he had started.

Stopping has never really been Mr. Brody’s thing. Even in his fallow years he made plenty of films and has kept up a busy schedule during the pandemic. He guest starred on “Succession,” as a billionaire investor who takes meetings on his private island. He has leading roles in “Winning Time: The Rise of the Lakers Dynasty,” an upcoming HBO drama series; “Blonde,” a Marilyn Monroe biopic on Netflix; and “See How They Run,” a period crime film.

He also stars in “Clean,” a new movie on Amazon Prime Video that he co-wrote. Mr. Brody, who plays the title character, a sanitation worker with a strict moral code and a talent for ultraviolence, also composed the film’s score.

He doesn’t see painting as separate from his acting. Or writing. Or music. “Oddly, they are so intertwined,” he said. “They’re all an extension of mind and heart and tumultuous stuff that is going on within.”

He surveyed his skull and placed it against a trestle table to dry. He might apply some gold leaf later. Or work the background a bit more. But the piece, he thought, was mostly finished. He seemed pleased.

“I want to apply all my energy to things that I find interesting and creative,” he said. “And bring a kind of beauty, a tormented, twisted beauty to the world.”