Over break, I indulged in watching many films, with one of them being Demon Slayer: Kimetsu no Yaiba Infinity Castle. Having already read the manga, I was eager to see how the studio would translate such a deep arc into animation, especially since there had been so much discussion online about its production, given that it took Ufotable 3.5 years to complete the film. Needless to say, the animation lived up to the wait, and after seeing the scale of the animation, I now understand why the next part is projected for release in 2027.

This made me curious about what truly goes into animating a film like this. I always assumed animation was a straightforward, digital, hand-drawn process. However, according to an article by Brandefy, Infinity Castle relies on a “seamless fusion of traditional 2D drawings and advanced 3D animation”. While many anime today incorporate CG, Ufotable has perfected a method where digital elements enhance movement rather than disrupt it. Their shots feature dynamic camera paths, detailed backgrounds, layered lighting, and fluid character motion that feel unified rather than separate.

One of Ufotable’s most powerful techniques is “satsuei”, the Japanese term for compositing. This stage merges characters, effects, backgrounds, lighting, shadows, and camera movement into a single frame. Ufotable approaches compositing the way a live-action film crew approaches cinematography. They adjust lighting effects, atmospheric layers, and depth of field to create scenes that feel immersive and alive.
This explains why film looked the way it did. The shifting architecture of the castle, the pace of the battle sequences, and the glowing breathing techniques are not just aesthetic choices. They are the result of months spent animating one scene, then refining it through digital layering until it feels alive. When the film moves through twisting hallways or throws characters through collapsing rooms, the animation isn’t just depicting motion, it’s essentially engineering it.
Understanding this process made me appreciate the film even more. What seemed like a simple viewing experience is actually the outcome of years of technical labor. With that in mind, the wait for the next part feels justified.
Source: https://brandefy.com/ufotable-anime-video-production-demon-slayer/














