Good grief, Charlie Brown, it’s a miracle—a sweet, charming animated children’s movie that, in this day and age, entirely eschews the potty humor all too endemic in modern “family fare.” Though it opts for computer-generated 3D visuals, “The Peanuts Movie” is otherwise completely true to its roots in Charles Schulz’s venerable newspaper strip and the series of classic television specials based on it. And in truth it doesn’t take more than a few minutes to adjust to the new visuals, which prove an almost perfect contemporary reflection of Schulz’s simple style. The result, as scripturally-savvy Linus might say, is some delectable old wine in a spiffy new bottle.

The fidelity to its source can be explained by the fact that good deal of the picture, written by Schulz’s protective son Craig and grandson Bryan (with input from the latter’s partner Cornelius Uliano), consists of bits that will be familiar to long-time fans from previous incarnations of the characters in print and on the tube, where their repetition was an important part of the fun. Swaths of Vince Guaraldi’s much-loved music from the TV shows are inserted into Christophe Beck’s score as well—as are Bill Melendez’s vocal contributions as Snoopy and Woodstock.

But those elements are woven into a plot that finally sees a resolution of Charlie Brown’s long-time infatuation with the unnamed little red-haired girl. In this telling, she’s the new neighbor of perennial lovable loser Charlie (voiced by young Noah Schnapp), who’s immediately smitten but gets weak-kneed at the very thought of approaching her. Lucy (Hadley Belle Miller), the local buttinski with the lemonade-stand psychiatric clinic, advises him that to win her over, he’ll need to be a winner at something—which will lead him into a series of efforts to do just that. But every time he approaches the victor’s circle—at a school talent show, on a standardized test, at a dance—something will intervene to return him to the figure of “good old Charlie Brown,” sometimes merely referred to (especially by Lucy) as “that blockhead.”

Meanwhile his perpetually scene-stealing beagle Snoopy goes into imaginative overdrive, inspired by the model plane Linus (Alexander Garfin), Lucy’s sensitive, supportive brother, has built for show-and-tell, takes on his familiar role as the World War I flying ace out to defeat the Red Baron. In this incarnation he’s given a love interest, too—a French poodle named Fifi (Kristin Chenoweth), whom he must rescue from his rival in flying combat.

These two overarching plot threads dominate—and it’s arguable that the canine one gets too much screen time—but they provide a pleasant skeleton for the cherished short skits grafted onto them, in which other characters like Charlie’s sister Sally (Mariel Sheets), tomboy Peppermint Patty (Venus Schultheis) and her long-suffering helpmate Marcie (Rebecca Bloom) and Lucy’s Beethoven-loving would-be boyfriend Schroeder (Noah Johnston) play their parts. (Schroeder gets a clever cameo in the opening Twentieth-Century Fox logo as well.) By today’s standards the result is extremely gentle and soft-grained—even Snoopy’s aerial derring-do is mild—though not to the extent of the Disney “Winnie the Pooh” films, for example. But that’s all part of the plan to take us back to an earlier era, before the wacky, often tasteless frenzy that characterizes most so-called family films nowadays. The presence of rotary telephones and typewriters—no smart phones or word processors here—is part of that concept, too.

So Steve Martino’s film brings Schulz’s classic creation up-to-date in technical terms while remaining faithful to the spirit and tone of the beloved strip. Even its transformation into one of the great merchandising entities of the late twentieth century didn’t ruin “Peanuts,” and neither will this movie, which is too engaging to be simply dismissed as a nostalgic tribute. It fills that role, to be sure, and does so well; but you don’t have to be a long-time fan to enjoy it.