The Gorge

Among the standout visual developments was the creation of the mutated, woody creatures inhabiting the Gorge, with the most challenging being the Hollowmen. These former soldiers, trapped in the Gorge, have been transformed by toxic plumes into grotesque, tree-like beings.

Building on initial head designs provided by the production team, Framestore’s Art Department, led by Martin Macrae, extended the concept to full-body forms. “Our task was to create bodies with costumes that would complement and incorporate the pre-designed Hollowmen heads,” says Macrae. “The challenge was to include plant life native to the environment while reflecting dramatic mutations caused by the radioactive valley. The Hollowmen needed to remain recognizably human, as if they were trapped within their own bodies."

Of all the Hollowmen, Alpha, the dominant one, required the widest range of motion and direct interaction with the actors. Bringing him to life demanded a careful balance of practical performance and CG enhancement, preserving the nuances of the on-set performance while transforming him into a more imposing, otherworldly figure.

The team replaced the actor’s body with a fully CG design, introducing key anatomical changes such as elongated fingers, a narrower waist, and broader shoulders. However, facial and prosthetic elements were retained in most shots to preserve the original performance. 

Each shot was meticulously analyzed to determine how much of the practical performance could be retained. In many cases, the actor’s facial expressions, sweat, and eye movement were preserved to enhance realism. In some shots, only the mouth was kept. This process involved precise body tracking, subtle animation to match proportions, and refinements to ensure seamless integration.

The other hero Hollowmen and their multiple variants were entirely CG and were designed by the team from the ground up. Multiple versions of the Hollowmen were developed by swapping costumes, adjusting textures, modifying grooming and vegetation features, and altering shading to reflect their environment, but they all shared the same base.

Beyond the Hollowmen, Framestore also created a host of other creatures from concept to final render, including the Hazmat, Hollow Horses, a massive centipede camouflaged as tree roots, and sap-trap root creatures, further enriching the eerie ecosystem of the Gorge.

Framestore created several visually-rich, but certainly dark and ominous environments transporting audiences into the depths of the hidden gorge. From dense, surreal forests to desolate wastelands, the team meticulously crafted the unsettling ambiance of the lower gorge. The lower gorge is perpetually shrouded in CG fog, an ever-present, toxic force that transforms humans into Hollowmen. More than just an effect, the fog is a character in itself, appearing in all its shapes. 

Most of the lower gorge environments were seamlessly CG-extended from their soundstage builds, preserving the tactile realism of practical sets while vastly expanding their scale. Multiple layers of complex atmospheric effects like hazy fog, billowing plumes, and intricate particle simulations were applied. Achieving the right atmospheric balance was critical to build the film’s haunting aesthetic while maintaining visibility for key action beats. The team leveraged their expertise by adapting techniques from previous projects, such as the tracer fire setup from Rebel Moon. 

The team also played a key role in shaping the above-ground environments, designing and building fully CG abandoned military facilities seamlessly embedded within an eerie, fog-filled landscape. Inspired by 1950s and 1960s military architecture, the team built out the military base with logical layouts, featuring housing, main road, and secondary roads, fuel processing stations, maintenance buildings, and electrical infrastructure. To reinforce the abandoned, decayed feel, artists integrated overgrown vegetation, rusted machinery, and scattered debris. Ground surfaces were richly detailed with rocks, pebbles, and remnants of past activity. 'It was a lot of information to capture in a single image," explains Sita. “It was also a fine balance as to how far we should go in terms of details, knowing the ever-present plumes would obstruct the shot's clarity.  We experimented with fog density, ensuring that close-up shots had enough moody atmospheric depth, while wide hero shots retained clarity."

Finally, the team executed a massive nuclear explosion. Using real nuclear test footage from the 40s and 50s as a reference, they crafted an explosion that balanced sheer scale with the precise timing required by the director. “The explosion needed to feel almost like slow motion, hitting all the key beats—the initial blast, the shockwave, and finally, the dust occluding the camera,” explains Sita. “Although complex, we successfully delivered large-scale destruction that feels both vast and cinematic.”