After a scene-stealing performance from Mark Ruffalo and his CGI counterpart, The Incredible Hulk, in The Avengers, Marvel has finally secured some big screen traction for the mean green machine. Hulk was central to a number of fan-favorite moments in the superhero mash-up movie and, even if some naysayers still found the character underwhelming, many moviegoers were blown away by director Joss Whedon’s success in blending the CGI character with a live-action ensemble.

Unfortunately, fans will have to wait until after Avengers 2 hits in 2015 for a new standalone Hulk movie but, at the same time, there’s plenty of reason to be optimistic that further blockbuster Bruce Banner appearances will deliver equally believable and enjoyable on-screen smash action. Why? Because Marvel has learned that there’s more to the character than just a “pissed off rage machine.”

We already delivered our interview with Jeff White, an ILM Visual Effects Supervisor on The Avengers, who addressed the potential difficulties of Guillermo del Toro’s proposed Hulk TV series. However, our conversation with White, as well as Associate Visual Effects Supervisor, Jason Smith, wasn’t just about “phase two” – the Industrial Light & Magic gurus also discussed how they collaborated with Whedon, plus other effects studios, to deliver the most believable and complex Hulk character ever seen.

While the filmmakers knew they’d have to get a lot of minute details correct, one of their biggest challenges was giving the CGI character a range of emotional states – not just “angry monster.” The key, according to White, was to dig into the man behind the monster, Bruce Banner/Mark Ruffalo:

Previously Marvel had decided that the Hulk shouldn’t look like an actor, he should be timeless. He could be played by anybody and the Hulk is the Hulk. I think what they realized for this one and what Joss really pushed was you should be able to see Mark Ruffalo when you look in the Hulk’s eyes. And that connection to the actor was probably the biggest difference for us. Just being able to have filmed plates of Mark Ruffalo to look at – what do his eyes look like, what does his skin look like, and then be able to really replicate that into the Hulk made a huge difference in terms of getting those little idiosyncrasies in there. In the same vein, as time progresses, so does quality of skin shaders and the ability to do muscle simulation and hair rendering and all those things too. Technology, since the last time we did the Hulk, which was pretty much when I started, a lot has changed in the last ten years in terms of speed and what we are able to do for him.

Following a presentation of featurette material from the recently released Avengers Blu-ray release (read our review), ILM Avengers Animation Director, Marc Chu mentioned that the team spent a lot of time trying to keep the Hulk from looking “too tense.” It was an especially interesting comment – given that most people think of the character as little more than a unflinching force of nature when “Hulking out.” However, comic book fans know that Hulk still features emotional complexity, not just one-note angry face – especially the “Smart Hulk” version included in The Avengers.

As a result, we were sure to follow up on Chu’s comment when I sat down 1-on-1 with White.

He’s got these moments with Captain America and down on the viaduct where, sometimes when he’s standing there he is tense and ready, he’s going to fight all these aliens but there’s other times where he’s got a quieter moment at the end and you’ve got to figure out what does the Hulk do when he’s not pissed off and raging all the time. And that took awhile and even down to his physique, we did want to make sure, Joss wanted that kind of wrestler, big heavy, maybe couple extra pounds look to him – so that when he did get pissed off you felt that angular cutting. And actually we spent a lot of time rendering multiple passes of lighting just to get that chizzled jaw and that cut line along the cheek because our first render he almost looked fat and nobody wants to see a fat faced Hulk.

Looking back to the prior Hulk film’s especially Ang Lee’s 2003 Hulk, it’s easy to appreciate what Whedon and the effects teams have done with the character – as creating a more grounded and emotive Hulk will serve the character well down the line (in Avengers 2 and future solo films). This isn’t to say they need to soften him up – but giving the character a more natural baseline (instead of “on” or “off”) makes it even more impactful when he’s in full-on fighting mode.

Though, even if you’re able to deliver an extremely believable character, one that can express complicated emotions, matching the oversized CGI model in with a roster of live action actors was still a considerable challenge. However, the team was assisted in their efforts by a number of design choices – and, according to White, an extremely detailed character model.

Well, he doesn’t fit that well and camera framing is a big issue – how do you keep all of the Avengers and this guy who is 8 feet tall. And I think part of that was a conscious decision by Joss that, like, he shouldn’t be walking around upright like John Hamm all the time. Get him hunched over and get him tense and that way you bend him down into the frame with the rest of these guys. It came down to some initial really good design decisions by Joss – in terms of what [the Hulk] body structure looks like, letting us put body hair all over him. That’s something, you know, that fans could have reacted very negatively to, sort of hairy-chested Hulk, but when you zoom in to his eyes, like everything’s there down to little nose hairs and I think that lends a lot of credibility. We built him top to bottom to hold up really close to camera.

ILM Associate Visual Effects Supervisor, Jason Smith, expanded on that point – revealing how the ILM team ensured that Hulk would look believable under close scrutiny – down to obsessing over individual hair follicles:

For the first time, he had beard stubble. And when we looked at his face, we realized it just looked CG. It looked like the stubble just goes to the face and stops and then there’s green skin. Then we looked at photos of people close-up and you can see, even though you think of skin as opaque, you watch that [hair] go into the skin and you see it underneath the skin. You see it continue. You can actually see the follicle, if you look close enough. And so with the Hulk, we had to incorporate that. We had to say all right the light bouncing around, the scattering inside his skin, darken it right at the root of the hair. So it’s a bunch of little incremental things like that where we notice some small piece of reality and say okay, let’s focus on that for a second. And then move on to the next one.

The Avengers 2 release date was announced the day of our interviews at ILM, so the visual effects leads didn’t have anything concrete to report about the sequel. That said, given their success with round one, it’s likely that Whedon will include Industrial Light & Magic among the roster of effects studios he’ll be recruiting for the 2015 film – and, despite the quality of the current on-screen character, the team already has a long list of improvements they’d like to address. Of course, in the mean time, they’ll likely (though unconfirmed) be testing their mettle with the other end of the spectrum, specifically Rocket Raccoon in James Gunn’s Guardians of the Galaxy.

For more on ILM’s work on the Hulk character, be sure to pick up The Avengers Blu-ray and check back soon for more Avengers coverage.

Follow me on Twitter @benkendrick for future interviews, as well as movie, TV, and gaming news.

The Avengers is now available on 3D Blu-ray, Blu-ray, and DVD.