The schools sit in a picturesque valley, with a lake running through its centre. The School for Good, a fairytale palace made of stone, is raised into the mountainside, whereas the School for Evil sits directly on the water, shrouded in mist. The environment is entirely CG, which allowed the team full creative freedom when building the fantasy world and designing the schools to represent their chosen disciplines.

“Our first introduction to this setting is when Agatha and Sophie arrive, in the claws of a skeletal bird known as a Stymph,” says Fawkner. “Our establishing shots follow this large creature, flying and swooping as it drops the girls in the lake.” Framestore Pre-Production Services were on hand, producing the entire sequence to make sure the environment was being showcased in the best possible way, and working out the scale of the girls, the Stymph, and the schools themselves.

“It was important for the team to keep within a boundary of believability - although the schools are a fantasy world, creating something that looks like a real, tangible place is part of the magic for the audience,” says Environments Supervisor Keir Longden. “We actually ended up re-designing and re-scaling the school exteriors once we’d seen the wonderful interiors so they could conceivably fit the inside.”

The team also took a crash course in landscaping and neo-Gothic architecture in order to design the grounds and exteriors. “It’s all about taking something magical and grounding it in reality” continues Fawkner. “We used Framestore’s forecast tool to offer novel and photogenic conditions within which to photograph the CG schools for the many establishing shots.”

Framestore was involved in the visual development of the Stymph creatures from the outset, working with Director Paul Feig to develop the look. “They’re well described in the books, which laid a solid foundation for us,” expands Fawkner. “Everyone was keen to give them some flight surface, something to provide wind resistance, and conceivably allow it to fly.” Feig drew inspiration from Terry Gilliam’s Time Bandits and went for a tatty feel instead of a bare skeletal creature. “We looked at desiccated and mummified birds to get the structure and behaviour right for the flaps of skin that hang off the bones,” continues Fawkner. “We ended up with a visually rich, layered, look that hopefully honours the Stymphs described in the book.”

One of the stand-out magical creatures that the heroines encounter are the fairies. “The fairies in the film posed a particularly technical challenge for us,” says Fawkner. “It was agreed very early on that they were not going to be your average Tinkerbell-style creature. As well as being generally more sinister, a key difference is that we don’t see their legs,” adds CG Supervisor Freddy Salazar. The movement of the fairies and their costumes was inspired by that of a jellyfish, and so their full-length costumes provided a large piece of cloth which had to look and feel like it was submerged in water, a hugely complex simulation.

Director Paul Feig was keen to capture as many human elements as possible, and so we used LED volumes with a motion control rig,” explains Fawkner. Framestore’s Pre-Production Services team were involved from the outset, establishing the camera angles needed to project the environment on the walls of the LED cage. This allowed the actors playing the fairies to react to their environment in real time, capturing their facial expressions, which were then expertly composited back into the scene at the correct scale, atop CG bodies.

“It was a complex set-up to be able to capture what we needed, using 360 degree cameras, which then went through many layers of compositing before the finished final shot” comments Fawkner. “Our studio in Mumbai made a heroic effort digitally painting out the crew holding the 360 degree cameras. When reviewing the footage I would have considered it to be impossible to remove, they did an outstanding job.”

The film is packed full of very different, stylised effects - fire, fog, and blood. When it came to defining the look and behaviour of these effects, the team began at the drawing board. “Our in-house art department started by producing a series of stills that allowed us to discuss first ideas and establish a look for these effects,” explains VFX Supervisor Ben Magana. “Then, when it was time to migrate to moving images on all these elements, we made the jump to VisDev. Having a single artist with multiple 3D/2D skills focused on each single effect was extremely valuable, as we managed to try different techniques in a much more nimble way.”

During her classes at the School for Good, Agatha discovers wish fish, who are said to be able to grant wishes found deep inside the soul. While her classmates wish for beauty and love, Agatha wishes for home, unknowingly freeing a young girl sentenced to eternity as a wish fish. What follows is a particularly tricky effect, as Agatha reaches into the water and pulls out a shoal of wish fish, gradually transforming back into a human as they break from the water. “Creating these very subjective effects was one of the biggest challenges for us,” comments FX Supervisor Keith Acheson. “We openly discussed each iteration, and had a brilliant dialogue with Paul Feig, allowing us to shape these effects to his liking.”