Russell and Carl share stratospheric adventures in “Up.”

Another year, another Pixar triumph. When is the infallible animation house going to release a lazy, pandering cheeseburger so we have something novel to say about it? The sublime “Up” suggests that the studio’s reputation for smart fun and creative integrity is nowhere near winding down.

From the title onward, “Up” is a stratospheric success. It’s guaranteed to lift your spirits, and not with a pushy DreamWorks-style gag reel of celebrity voices and committee-processed one-liners.

“Up” takes the high road. It’s the kind of work made by people who love original, risky ideas and get excited about supporting them. It’s whimsical fun, breezy and light-hearted, bouncing on buoyant charm, but soulful, too. Walt Disney decreed that in his animated features “for every laugh there must be a tear,” and so it is here. Real-life emotions make the humor ring true. It’s deftly poised between levity and gravity.

Set entirely in the human world, the hero of “Up” is 78-year-old Carl Frederickson. (With “Up” coming on the heels of Clint Eastwood’s smash “Gran Torino,” we could be entering a golden age of grouchy grandpas.)

We meet Carl as a kid in the 1930s, imagining a life of daring exploits. He idolizes Charles Muntz, a high-flying explorer who vanished collecting rare animals from around the globe. Carl’s rambunctious young neighbor Ellie shares his yen for adventure, and a lovely dialogue-free montage follows their sweet relationship from contented marriage to old age.

They dream of traveling to South America’s mile-high Paradise Falls. But as life’s nuisances nibble at their vacation fund, the trip goes on hold. Carl dispenses happiness as a balloon vendor at the city zoo, and he has a warm home life, but the grand adventure he hoped for never materializes. As he ages, Carl becomes, literally, a square. At 78, his body resembles a stack of cardboard boxes. His head is a cube, his glasses rectangular. We know this old guy like a family member and care for him deeply.

Widowed and retired, Carl retreats into his gingerbread Victorian house. But the world keeps pushing in on him. He’s the last holdout against a skyscraper development that is rising all around the perimeter of his lot. Realizing that he never fulfilled Ellie’s getaway wish, he ties his surplus helium balloons to his house and floats away toward Paradise Falls.

To his shock he discovers that he has another passenger onboard. Eight-year-old Russell is a cheerful, well-meaning scout who has been hanging around Carl’s house in hopes of earning his Assisting the Elderly merit badge. The chubby, balloon-shaped boy’s endless chatter is annoying to Carl, but endearing to the viewers.

Drifting through lightning storms and near-collisions, they land in the high plateaus of Venezuela, the strange landscapes that inspired Sir Arthur Conan Doyle in writing “The Lost World,” and find artifacts from the lost explorer Charles Muntz. They discover a species of goony bird that’s half ostrich and half toucan, a pack of mutts fitted with collars that turn dog-thoughts into speech (“I have just met you and I love you”), and a menacing adversary.

The finale is a whiz-bang aerial battle between a zeppelin and canine-piloted biplanes — a literal dogfight. Amid the laughs and thrills, we never lose track of the connection growing between Russell and Carl, and the old man’s journey from grump to Gramps. The voice actors, gravely Ed Asner and the endearingly natural Jordan Nagai, have a great rapport.

“Up,” Pixar’s first venture into 3D, employs the process in a way that’s apt and awe-inspiring. “Up” is a movie made in 3D, not a 3D movie. Rather than stabbing you in the eye with spears, writer-director Pete Docter and his colleagues use 3D as a window into the characters’ world. Half of the film is set on a high plateau with sheer cliffs all around, and the drop-offs are vertigo-inducing. The character design is vintage Disney caricature, while the textures of objects onscreen have a stunning physicality. You can feel the weave of the textiles, the smooth heft of stones. It adds depth without calling undue attention to itself.

That’s the Pixar way. While the technique is dazzling, it’s the emotions, ideas and characters that count. “Up” tickles you silly but leaves you with worthwhile ideas to ponder. What is the adventure of a lifetime, anyway? A daredevil series of cliffhangers in a wild, exotic land? Or could it be committing yourself heart and soul to another person, forever?

There’s more than one way to take an amazing journey, even if it takes you 78 years to figure that out.