We here at Collider are excited to unveil some exclusive behind-the-scenes images from the making of Avengers: Endgame, which specifically reveal how one of the film’s scene-stealing characters was created. Indeed, with the five-year time jump at the beginning of the film, few could have predicted where we’d find Mark Ruffalo’s Hulk/Bruce Banner at this point in time. But the Avengers sequel offers up a version of Hulk we’ve never seen before, aptly named “Smart Hulk.” In the five-year interim, Banner perfected his formula and morphed himself so that his size and appearance were that of Hulk, but his brain was that of Bruce Banner. Add in some salt-and-pepper hair and a knack for sweaters, and you have yourself a brand new internet obsession.

Smart Hulk was brought to life by the folks at Framestore, who delivered over 300 shots of visual effects work for Avengers: Endgame. The company was primarily tasked with bringing Smart Hulk to life, and to begin they took source footage of Ruffalo that they could then match in animation. As it turns out, one of the most challenging aspects of bringing Smart Hulk to life was the facial build:

Smart Hulk’s facial build was particularly challenging, as VFX Supervisor Stuart Penn explains: ‘There was a lot of work involved as their face shapes are so different - Hulk is massive, his mouth proportionally bigger, his eyes are sunken with deeper sockets. Tiny changes to his face had a huge effect on the performance. ’A new subset of facial shapes was built to enable the animators to achieve more complex and nuanced expression and give them more control in the animation.

avengers-endgame-behind-the-scenes-mark-ruffalo-hulk
Image via Framestore/Marvel Studios

They succeeded wildly. You can really feel Ruffalo’s performance inside that animation that brought Smart Hulk to life, and it becomes particularly important during the scene in which Bruce learns Natalie isn't coming back.

The folks at Framestore were also tasked with animating Rocket Raccoon, who they originated for the first Guardians of the Galaxy and refined in Guardians of the Galaxy Vol. 2. They added some grey around his muzzle to reflect the time jump, but were careful to keep any changes subtle. Additionally, Framestore was tasked with animating the Quantum Realm suits that the Avengers team wore:

The actors had been shot in their individual outfits, so Framestore built digi-doubles before replacing the costumes on the ten characters made up of an array of body types and proportions; ranging from Rocket and Black Widow to Nebula and Hulk. Based on concepts provided by Marvel Studios, the artists built a prototype suit for Captain America that was then adapted for each Avenger. These suits then had to manifest over their original outfits using the nanobot technology Framestore developed for Iron Man’s bleeding-edge Infinity War suit. Their helmets, based on Ant Man’s, also needed to be built in CG and manifest in the same way over the actor’s face. ‘The helmet is a snug but mechanical design,’ adds CG Supervisor Robert Allman. ‘We used the nanobot tech to give the impression that it comes out of nowhere.’

That’s right, those Quantum Realm helmets were entirely CG. Beyond these highlights, Framestore’s work in Avengers: Endgame also included quantum effects such as the van and the time portal, as well as complex CG environments like the hangar base out of which the Avenges work and the establishing shot of Asgard.

Check out some great behind-the-scenes looks at their work below, including Smart Hulk himself.

avengers-endgame-behind-the-scenes-image-hul
Image via Framestore/Marvel Studios
avengers-endgame-smart-hulk-black-widow-captain-america
Image via Marvel Studios
avengers-endgame-smart-hulk-captain-america
Image via Marvel Studios
avengers-endgame-smart-hulk-image
Image via Marvel Studios
avengers-endgame-smart-hulk
Image via Marvel Studios
avengers-endgame-rocket-raccoon
Image via Marvel Studios
avengers-endgame-rocket-raccoon-image
Image via Marvel Studios
avengers-endgame-vfx-image-2
Image via Marvel Studios
avengers-endgame-vfx-image-1
Image via Marvel Studios