Directed by Josh Cooley (‘Toy Story 4’) and based on the Hasbro toy line, the origin story explores the friendship — and eventual animosity — between Optimus Prime and Megatron.

Anyone seeing a Transformers movie knows to expect many examples of the imaginative robotic transformations that give the films their name. But with the exception of 2018’s Bumblebee, they’ve been overlong, lumbering bores offering little to those who aren’t rabid fans of the Hasbro toys. It’s a pleasure, then, to report that the series’ first animated theatrical feature in nearly 40 years proves a thoroughly entertaining origin story that even the uninitiated can enjoy. Besides the raucous, de rigueur action sequences, Transformers One provides numerous witty jokes of both the verbal and visual variety and — surprise, surprise — genuine emotion. Consider this a franchise revitalized.

If you’ve ever wondered just how the antipathy between Optimus Prime and his sworn enemy Megatron came to be, this is the film for you. Superbly directed by Josh Cooley (Toy Story 4), it introduces the characters when they were mere lowly, non-transforming bots and underground miners on their home planet of Cybertron. (By the way, should any of these details prove inaccurate, please be advised that this critic is by no means a Transfan.) They also haven’t yet assumed their iconic names, and are here known as Orion Pax (Chris Hemsworth, amiably filling the estimable shoes of Peter Cullen) and D-16 (Brian Tyree Henry). As the story begins, the two form a fast friendship, fueled by their shared animosity for the elite Transformers who lord over them.

It all leads to the discovery that the society’s leader, Sentinel Prime (Jon Hamm, amusingly pompous), is not the authority figure he claims to be. In the ensuing existential conflict, the quartet also encounter such figures as the elder statesman Alpha Trion (Laurence Fishburne) and the nascent Decepticon Starscream (Steve Buscemi, whose uniquely eccentric voice should be required in all animated features).

Screenwriters Eric Pearson, Andrew Barrer and Gabriel Ferrari expertly weave together comedic and dramatic elements in their fast-moving story, which depicts the eventual rift between the two central characters in classically inspired fashion. Along the way, there’s plenty of fun to be had, with the film thankfully forgoing the current animation trend of pop culture references in favor of throwaway jokes delivered in deadpan fashion. (When one of the miners wakes up after becoming injured in an ill-fated attempt in a racing competition, he asks, “Did I win?” “You participated,” he’s informed.)

The gorgeous 3D-style computer animation is a wonder to behold throughout, from the character designs (these seem the most expressive Transformers yet) to the elaborate action sequences (the race is a highlight) to the varied settings that make the environments seem fully lived-in. There’s so much visual imagination on display that multiple viewings seem essential to take it all in.