Dmitri Nabokov, the son of Vladimir Nabokov, who tended to the legacy of his father with the posthumous publication of a volume of personal letters, an unpublished novella and an unfinished novel that his father had demanded be burned, died on Wednesday in Vevey, Switzerland. He was 77.

Nabokov was hospitalized for a lung infection in January and never recovered, Andrew Wylie, the agent for the Nabokov estate, said.

In contrast with his father, who was said to focus on literature and lepidoptery to the exclusion of all else, Dmitri Nabokov was a bon vivant, a professional opera singer, a race car driver and a mountain climber.

He was also devoted to the full range of his father’s work, including the early Russian writings like “King, Queen, Knave,” the English-language masterpiece “Lolita” and the unfinished novel “The Original of Laura.” He translated his father’s early Russian works, including the novel “The Gift” and the short-story collection “Tyrants Destroyed.”

He also wrote a memoir, “On Revisiting Father’s Room,” which explored their relationship as well as his father’s life and work. Nabokov also countered the widely held perception of his father as cool and distant, describing a “trusting, gentle nature.”

“If there is a quality overlooked in his writing by some of the more obtuse commentators,” he wrote, “it is that gentleness, coupled with a total honesty on every plane and an utter freedom from anything cruel, cheap or mean.”

In his book, Nabokov described an unpublished manuscript that he said “would have been Father’s most brilliant novel, the most concentrated distillation of his creativity, but whose release in incomplete form he expressly forbade.” Vladimir Nabokov’s widow, Vera, never burned the handwritten notecards that made up the novel, and in 2009 the younger Nabokov published it. The volume included a text of the book, in the order that the younger Nabokov believed his father had intended, but also facsimiles of the notecards, which could be detached and arranged in whatever order the reader preferred.

In an introduction, he wrote that his “father’s shade” would not “have opposed the release of ‘Laura’ once ‘Laura’ had survived the hum of time this long.”

In “Laura,” Nabokov “imagines the death of his protagonist, a writer and neurologist named Philip, as a sort of Nietzschean act of will, as an exercise in self-erasure conducted body part by body part, beginning with his toes,” Michiko Kakutani wrote in a review for The New York Times. “It is the ultimate fantasy of a writer who wants to exert complete control over the narrative of his own life.”

Kakutani said the book did “a disservice to a writer who deeply cherished precision and was practiced in the art of revision,” but she said it would “beckon and beguile Nabokov fans.”

Dmitri Vladimirovich Nabokov, an only child, was born May 10, 1934, in Berlin. In 1937, the family fled Germany for France and by 1940 had made its way to New York.

Nabokov concentrated on history and literature at Harvard and graduated in 1955. He also began training for the opera at the Longy School of Music in Cambridge, Mass.

In the late 1950s, Nabokov helped his father translate his novel “Invitation to a Beheading.” In 1959, he traveled to Italy and began training with a singing coach at La Scala in Milan. He later made his operatic debut in “La Boheme” alongside Luciano Pavarotti, then a novice tenor. An imposing presence onstage at well over six feet tall, he continued to sing professionally until 1982.

He also raced cars competitively until 1965.

In 1986, he published his translation of “The Enchanter,” a never-published 1939 novella by his father widely considered a forerunner of “Lolita.”

After his mother died in 1991, Nabokov moved into her apartment in Montreux, where he oversaw the Nabokov estate and where he lived at his death. He never married and has no immediate survivors.

In his memoir, Nabokov recalled one of his last exchanges with his father, who died in 1977. They spoke of butterflies, and of a bucolic valley near their home in Switzerland that they had always meant to explore.

“Tears suddenly welled in Father’s eyes,” Nabokov wrote. “I asked him why. He replied that a certain butterfly was already on the wing; and his eyes told me he no longer hoped that he would live to pursue it again.”