WASHINGTON — Just this once, I wish I could write with pictures instead of words. That would make it easier to explain why the Brazilian architect Oscar Niemeyer, who died Wednesday at 104, was one of my heroes.

Not for his politics, of course — he was, to the end, an avowed communist — but for his glorious buildings, which are freedom itself, sketched in concrete and glass. It is ironic that a man committed to an atheistic ideology designed one of the great religious structures of the world, the Metropolitan Cathedral of Our Lady Aparecida, in Brazil’s futuristic capital, Brasilia.

You’ve seen the cathedral in photographs. It looks like a giant teepee with poles of concrete, the sloping walls made of brilliant stained glass. The poles almost meet at the apex, but not quite. Instead, they curve back outward in what looks like a gesture toward heaven. Inside, the great conical space is bathed in blue light from the vast stained-glass walls. It is a transcendent place of worship, a space-age Chartres.

When I was in high school, I wanted to be an architect. This ambition — which was absurdly misdirected, as I learned at college in Architecture 101 — was primarily stoked by the work of Niemeyer, which I found electrifying.

I was fascinated with the audacity of Brasilia. Urban planner Lucio Costa, Niemeyer’s mentor, laid out the city in the shape of an airplane, with residential neighborhoods along the wings and monumental government buildings running the length of the fuselage, flanking a greensward reminiscent of the National Mall in Washington.

But the buildings Niemeyer designed for Brasilia were not standard-issue neoclassical. They were modern — but not austere. They were something else, something new. The stark unadorned angularity of contemporary architecture was softened by curves. Niemeyer’s buildings were human, whimsical, sensuous. They were sexy.

The Planalto Palace, where Brazil’s president works, could have been just a glass-walled box; Niemeyer gave it what looks like stylized, upside-down flying buttresses. The Itamaraty Palace, which serves as the foreign ministry, could have been boring; Niemeyer surrounded it with a moat-like reflecting pool, and for the interior designed a breathtaking cantilevered spiral staircase.

And at the end of Costa’s great esplanade, Niemeyer designed an iconic structure to house the Brazilian Congress. It’s like an assemblage of strange building blocks. On a low rectangular base sit four huge forms: twin narrow towers in the center and big concrete hemispheres on the ends, one facing up and the other facing down.

Why the hemispheres? Why not? Most great architects seek to impress, edify, instruct. Niemeyer wanted to surprise and delight. His work was serious, and taken seriously — he won the Pritzker Prize, architecture’s greatest honor, in 1988 — but there is a playfulness about his buildings that I find irresistibly charming.

He always said the curviness of his work was an homage to the female form — appropriate, I suppose, for a man who often sketched out his ideas while overlooking famed Copacabana Beach. “Form follows function” is the credo of modern architecture. Niemeyer said his motto was: “Form follows feminine.”

I don’t know of any architect who has had more impact on the look and feel of a nation’s built environment than Niemeyer has had in his native Brazil. He did important work abroad — he helped design the United Nations headquarters complex in New York — but most of his amazing output is in his homeland.

He continued to work on projects as recently as last year. Perhaps the best-known of his more recent buildings is an art museum in Niteroi, a city on the other side of Guanabara Bay from Rio de Janeiro. It looks like a flying saucer that chose to land next to the bay. A long, sinuous ramp that leads to the entrance has no visible support. Why the UFO motif? Why not?

One of my favorite Niemeyer creations is the Sambadrome. It is essentially an enormous set of grandstands, lining a busy Rio de Janeiro street, that during Carnaval is transformed into the site of a two-day parade competition among the city’s elite “samba schools.” It says something about Brazil that officials would commission the nation’s most acclaimed architect to design a 90,000-seat venue intended for the sole purpose of partying.

Rio de Janeiro Mayor Eduardo Paes declared three days of mourning in Niemeyer’s honor. President Dilma Rousseff said that “Brazil today lost one of its geniuses.” So did the world.

Eugene Robinson is a Washington Post columnist. His email address is eugenerobinson@washpost.com.