An excerpt from issue #37 of befores & afters magazine, which is all about models and miniatures.Netflixs Bullet Train Explosion (Shinkansen Daibakuha), from director Shinji Higuchi, tells the story of a bomb threat made to blow up an E5 Series Shinkansen bound from Shin-Aomori to Tokyo, if the train slows down below 100 km/h. For key moments of sections of the train crashing and exploding, the production utilized miniatures.Visual effects supervisor Katsur Onoue tells befores & afters that the decision to use miniatures, rather than relying solely on digital visual effects, was driven by the desire to create some distinctive and unpredictable imagery, plus tap into Japans rich history in using models.In Japan, says Onoue, miniature techniques have been widely used in films since the 1940s, and the craft has been handed down over generations. Its one of the techniques that Japanese cinema excels at. Director Higuchi and I were both raised in the world of special effects units and are very familiar with miniature filming techniquesboth their strengths and weaknesses.Planning the scenesTo help plan the crash scenes, Director Higuchi drew detailed storyboards. Animatics were also created and edited together. From the animatics, recounts Onoue, we selected the shots that needed to be done with miniatures and considered the filming methods and set designs. Because we could predict not only the scale and shooting methods but also many other aspects with high precision, we were also able to clarify the costs.Using the animatics as a base, we worked closely with the VFX team and the main units art department, clearly defining our respective areas of responsibility ahead of time and holding detailed coordination meetings, discusses Onoue. For example, in the rescue scene, the rear of the Shinkansen is shown damaged. The main unit had filmed their portion earlier, and the VFX team created 3D data and photographs of that set. We in the miniature team then used that data to recreate a perfectly matched miniature.It was important for all teamsVFX, art, and miniaturesto organize and share the information gathered from on-site investigations so that everything, from the main unit set to the miniatures, aligned as closely as possible with the real train, adds Onoue. We also scheduled production so that filming of the main unit set that would directly connect to the miniature would be completed before our miniature unit began shooting. This was necessary to ensure not only visual continuity in art direction but also consistency in lighting and camera work.Onoue also notes that the miniature units cinematographer served as the B-camera operator for the main unit and that the team shot elements needed for VFX compositing, such as explosion plates, water splashes, fire effects, and even shots of water being filled into the cushion drums, which the main unit couldnt capture.Building the miniaturesThe team then set out to determine the scale of the miniatures required, before building them. Since the shots to be done with miniatures were crash scenes, we decided that making the miniatures relatively large would increase the chances of success, says Onoue. After deliberation, we decided to create the Shinkansen cars and elevated track set at a 1/6 scale.Actual train blueprints from JR Eastnormally not available to the publicwere acquired to help accurately build the train. We also conducted research at a Shinkansen maintenance yard where we could observe up-close areas normally out of view, such as the wheels, undercarriage, pantographs, and paint details, outlines Onoue. We further enhanced accuracy by photographing and 3D scanning actual train cars.The art of miniatures: new issue of befores & afters magazine now out!The train body was built by laser-cutting MDF (medium density fiberboard) and then assembling the basic shape. The exterior and roof were coated with FRP (fiber-reinforced polymer), after which they were polished and painted. The windows were made of acrylic panels, and the wheels were metal machined parts. Notes Onoue: A sturdy aluminum frame was attached underneath the body, which connected via two 100mm-diameter iron pillars to a monorail dolly hidden below the set, allowing the miniature to move. Small parts like window frames, seats and nameplates were 3D-printed.An important part of the build was representing the damage on the train cars. We first created the train cars in a pristine, undamaged state, then redecorated them to reflect damage, advises Onoue. Crushed body parts were shaped by cutting out parts of the MDF frame and layering lead sheets on top. Passenger luggage was also loaded inside.Other items that would be part of the crash scenes were built, including the tracks and water cushion drums that feature spectacularly in one scene. Since no pre-made 1/6-scale rails existed, the team welded square iron pipes and L-shaped steel bars to make them look like rails. Around 200 water cushion drums were made, and then engineered to break easily. We printed the top and bottom parts as thin as possible with a 3D printer, wrapped thin plastic sheets into tubes, painted them, and applied weathering manually to each one, details Onoue.Filming the crashThe miniature train crash shots depict the train sliding laterally at an actual speed of 100 km/h. Converting this to a 1/6 scale meant the miniature needed to move at about 40 km/h during filming. The speed of the camera and the model Shinkansen were synchronized to help achieve the crash. To do that, a monorail was installed beneath the set to move the Shinkansen. Then, a mechanism was devised so that the camera car and the dolly moving the train would run in the same direction and at the same speed. Ultimately, notes Onoue, the power of the camera car itself was used to pull the dolly carrying the miniature Shinkansen.In real scale, the derailed car (Car No. 8) continues moving for about 1,200 meters before coming to a stop, continues Onoue. Reproducing this entire distance with miniatures was unrealistic and inefficient. Upon analyzing the animatics, we realized we could break the scene into three main segments. Each segment required only a 20-meter-long elevated track set. Luckily, most Shinkansen tracks are elevated straight lines with consistent visual appearance. So, by altering the background in each part with VFX, we could create the illusion of a 1,200-meter journey.In order to accelerate the camera car to 40 km/h as well as maintain speed over the 20-meter set, while also allowing for safe deceleration, it was determined that a paved run of about 80 meters was required. This was based on the drivers judgment, says Onoue. We paved a 4-meter-wide, 100-meter-long stretch of a borrowed open space and installed an H-beam monorail over 80 meters long parallel to it. The camera car was equipped with three cameras mounted on an isolator arm, plus three fixed cameras and a drone that flew simultaneously. Additionally, two small cameras were mounted directly onto the miniature Shinkansen. At most, seven cameras were used in a single take.For the crash and explosion, debris and water became a significant part of the final look. Cushion drums were filled with water to soften the impact. In actual footage, when these are destroyed in a crash, they produce dramatic sprays of water, notes Onoue. Although the miniature cushion drums were designed to break easily, the impact alone wasnt sufficient to produce the desired effectso we decided to use explosives to assist in their destruction.However, says Onoue, water doesnt scale down like a physical object. To simulate the water splash, we used a substitute material that would look like water droplets when dispersed. In this case, the material was called Hakuryu Saiseiki, a construction-grade white crushed limestone mixed with salt. We exploded this material using effects-grade explosives timed to the moment of impact.Meanwhile, the droplets streaming down the train body were created using milky-white wateressentially water mixed with milkand blasted with air cannons. Inside the train, photographic flash bulbs were installed to simulate the flickering of short-circuited electrical sparks. We also embedded blowers inside the Shinkansen to blow away dust scattered on the tracks, states Onoue. Ballast, which was crushed stone on the tracks, was also blown away using air cannons. As for sparks flying from under the vehicle, we filmed real sparks by grinding iron with a grinder and then composited that footage into the scene.In the end, the miniature train cars weighed approximately 300 kilograms. This posed a unique problem of designing models that could withstand sudden acceleration and vibration, yet still break apart as needed, despite the conflicting engineering demands. We prepared two cars specifically to be destroyed and captured the crash in two takes using seven cameras, describes Onoue.Ultimately, the first take was the one used in the final film. As for the shots involving the cushion drum impacts, those were broken up into three sequences, with each sequence filmed in two to three takes. Additionally, the freight train explosion at the beginningset off by the culpritwas also done with a 1/8 scale miniature.Read the full story in the magazine.The post Orchestrating a Bullet Train Explosion appeared first on befores & afters.