It took “Toy Story 4” to prove to Disney and Pixar that maybe they should’ve let the trilogy end on a glorious high note, rather than milking it for one extra movie.

But here is “Lightyear,” a spin-off adventure that aims to wring a little more lucre out of Pixar’s best idea ever. No, it won’t make anyone forget “Toy Story 3” either.

The conceit is that “this is the movie” that so-obsessed little boy Andy that he had to have that Buzz Lightyear action toy for his birthday. What Pixar set out to do, with some of the most impressively-detailed CGI animation ever and a few epic action beats, was create a straight-up sci-fi adventure that would appeal to a little boy still young enough to play with dolls.

They recast Buzz with Captain America himself, Chris Evans, a handsome charmer in live action films, and a guy who can be funny. Just give him a funny line and he’ll nail it. Again, just give him a funny line.

But without the irony of Buzz thinking he’s real, even though he’s just a toy come-to-life, with lots of other exasperated toys trying to shake him out of this dogmatic belief, without Tim Allen’s deadpan egomania rubbing up against Tom Hanks’ folksy exasperation, “Lightyear” has given up its best laugh.

And the replacement gags — mainly via Sox (Peter Sohn), a robotic, multi-tasked talking cat who is a combination of R2D2 and C3PO — are never remotely as original or as amusing as that.

Taika Waititi and Keke Palmer also provide voices, and Isaiah Whitlock Jr. and Erfren Ramirez. And they’re voicing characters so colorless almost anybody could have replaced them, with only Waititi’s quizzical Kiwi way with a line adding even a hint of humor to the proceedings.

The story — Buzz is a Space Ranger with a tendency for going it alone, wanting to be the hero, and a gift for screwing up.

He “narrates” his story into an imaginary “log,” a running joke amongst his fellow Space Rangers at Star Command. Yes, he takes it all terribly seriously.

Buzz is part of the first-to-wake crew on a huge cryo-sleep spaceship that he nicknames “The Turnip,” because “the ship looks like a root vegetable.” That’s it. That’s the joke.

They get a diversion signal (straight out of “Alien”), causing them to go off course and land on a planet with swarming, tentacled beasts occupying its underground. Buzz botches the escape liftoff, and there they are, a large group of humans stranded on a planet, unable to call for help (apparently), forced to build and DIY their way out of their doom.

They need to synthesize an alternate power source. Buzz will pilot a shuttle/fighter craft into hyperspace and go for help. “Finish the mission” is the Space Rangers’ code, and he’s determined to do just that.

But every test fails, and with every failure, Buzz’s guilt, his “court martial myself” doubts, grow. With every failure, time dilation means that his fellow crew and colleagues, including his biggest champion, Captain Hawthorne (Uzo Aduba) age years, while Buzz stays the same.

He’s trapped on the “Edge of Tomorrow,” repeating himself. And he’s not learning from his mistakes.

But his last return from a failed test flight finds that his nemesis, Emperor Zurg (James Brolin), has shown up with his own ship, menacing and threatening to enslave or wipe out the nascent colony. Hawthorne’s granddaughter (Palmer) and a couple of colorful sidekicks (Dale Soules and Waititi) are ready to pitch in, but Buzz still has his own “I can get us out of here” ideas.

The movie’s theme is summed up in a single sentence — “We don’t need you to rescue us, we need you to join us.”

The predictable action beats are recycled from lots of similar sci-fi movies with the only difference being that here they’re animated. It’s a great looking movie, no doubt about it.

There’s more message than laughs or heart in the screenplay, which has Buzz soul-searching his way out of the trap that his ego has become. It’s also constructed in ways that maximize representation — many races, a gay couple, etc.

But what little wit there is was confined to the Xmas Toy to be Sox, a robotic Swiss Army knife of save-the-day, deus ex machina gimmicks that extract Buzz & Co. from many a fix.

A “real” Andy would’ve probably preferred Sox as a birthday present to Buzz, I dare say. But honestly, I didn’t find much in “Lightyear” that any kid, or adult, would obsess over. Impressive as it looks, it’s emotionally lacking, humorless and kind of dull.

Pixar turned out the light and left out the joy.

Rating: PG for action/peril

Cast: The voices of Chris Evans, Keke Palmer, Peter Sohn, Uzo Aduba, Efren Ramirez, Dale Soules, Mary McDonald-Lewis, Isaiah Whitlock Jr., James Brolin and Taika Waititi.

Credits: Directed by Angus McLane, scripted by Jason Headey and Angus McLane, based on a character created by John Lasseter. A Pixar/Walt Disney release.

Running time: 1:40