In fact, Whedon, Ruffalo, and ILM took inspiration from Lou Ferrigno's popular TV performance. He was a believable physical presence, who flexed his muscles but whose physique had a smooth flow. "He was real and there's something very physical about his performance and we wanted to make sure that we replicated that so he didn't feel disconnected once we put him in a scene with live people," explained animation director Marc Chu.
And thanks to advancements in facial performance capture, new rigging, and procedural skin shaders, ILM got the Hulk just right. The detail in the skin is spot-on right down to the pours; and the extreme poses have the correct muscle mass. Plus, it helped having a great performance from Ruffalo. He was as much an unexpected pleasure as Robert Downey Jr. was when he debuted as Iron Man. Like the film overall, Ruffalo isn't too serious or silly. "The scene between Hulk and Loki's almost a Hanna-Barbera moment," remarked associate VFX supervisor Jason Smith. "But as it came together, that's exactly what viewers wanted to see the Hulk do."
But "The Avengers" is far more than the Hulk in its coalescence of several Marvel worlds. ILM also tweaked Iron Man, making him more nimble and less constrained in his new Mark VII suit than in his previous two standalone movies, which was another Whedon directive. "We're back to a round RT on his chest but the biggest change was giving him a rocket pack," added VFX supervisor Jeff White. "That was a conscious decision by Joss to give Iron Man different poses and not have his hand always as part of the thrust component. We also provided a little extra weaponry with a hand laser and thigh missiles."