In the process of film and television production, under what circumstances can you cross the axis without leaving the axis?

First, a single mirror passes through the shaft. So there is no sense of visual suddenness.

The audience saw the process of crossing the axis. This situation may be caused by the camera movement in the movie, or it may be caused by the off-axis movement of the character object.

Second, the polygon mirror spans the axis.

1 The viewing angle (or camera) is on the "axis" before passing through the axis. Some filmmakers call it riding. As long as there is such a line riding lens before jumping off the axis, off-axis will not bring too much sudden feeling.

Switch the subject or scene before the 2-axis intersection. There's nothing to say about this. In fact, I think the audience's sense of space has been destroyed, so the "axis" has no psychological basis when changing scenes.