You have to use the “comp camera” switch within the shatter effect.
AE only works with flat planes in 3D space. Any “3D” effect such as shatter just creates a “movie” of a 3D effect which “plays” on one of AE’s flat layers, which acts as a “movie screen”. If you have a 3D camera, you should activate the “comp camera” switch, so the 3D shatter “movie” uses the comp camera as its “camera” and the “movie” looks “right”.
That’s why the shatter layer should stay 2D, flat to the viewer, as if the shatter “movie screen” layer were flat to the viewer. If you make the shatter layer 3D, and view it at an angle, it is like viewing a movie screen at an angle, which looks odd.
You see?
Steve