Ryoto-Kato

I had also encountered this issue due to `(cx, cy) != (width/2, height/2)` because [getProjectionMatrix()](https://github.com/graphdeco-inria/gaussian-splatting/blob/0b3519bca56e0ab38f85d5aa15d8aae7f526a4fe/scene/cameras.py#L55) assumes `(cx, cy) == (width/2, height/2)` In order to adapt to the non-zero principle point...