>>17393668The background screen lagging behind on low-FPS makes no sense from computer graphics perspective. They already have all the info required for rendering in the first place, they could portray the scene from arbitrary amount of cameras. The performance should also be a non-issue, there's nothing particularly difficult in the rendering tech they're using. Of course it's by no means easy to make an appealing anime-style rendering, but the problems therein have been solved ages ago.
What's difficult is the realtime mocap that made this possible in the first place. That's honestly been at all possible for less than 10 years on a commercial level. When you account for the tools programming work or so-called productization required, it's no wonder it took us so long to be able to enjoy dancing anime girls now.
t: anon working in graphics programming for more than a decade