WASHINGTON (AP) ― Chinese artist Ai Weiwei, who helped design Beijing’s Olympic Stadium and has since drawn tough scrutiny for his political activism, is opening the first North American retrospective exhibition of his work in Washington.

Ai, 55, is barred from leaving China, though, after being detained without explanation for three months last year. In recent weeks, he has been fighting charges of tax evasion, and the government has moved to close his design firm. So he will not be at the opening Sunday at the Smithsonian’s Hirshhorn Museum.

Artworks in “Ai Weiwei: According to What?” capture his push for free expression and his relentless questioning of authority, curators said. One 1995 photograph shows him giving the middle finger to the White House. It’s also a study on perspective that Ai has repeated at the Eiffel Tower, Tiananmen Square and elsewhere. 

“I always admire his questioning attitude. I think it’s important for all of us to try to find the truth and where the truth is,” said curator Mami Kataoka of Tokyo’s Mori Art Museum, who organized the exhibit. “It’s very difficult to find the truth, particularly in China.”

Planning for the exhibit began years ago, long before Ai was detained for 81 days during a crackdown on dissent. The installation includes sculpture, photography, video and audio works, encompassing most of the museum.

In a statement to the Smithsonian, Ai said the exhibition was a chance to communicate with far away audiences. “It is part of a continual process of self-expression,” he said.

The show is on view through February before traveling to Indianapolis, Toronto, Miami and New York City.

It includes new works created since the last major exhibition in Tokyo. One piece involves 3,200 porcelain crabs called “He Xie.” The Chinese words for river crab sound like the Chinese word for “harmonious,” part of the Communist Party’s slogan of “the realization of a harmonious society.” The term has become Internet slang for online censorship.