An ordinary +90° camera that sees exactly what buildCubeFaceCamera
sees: the −90 fov negates both NDC axes, which is a 180° roll about the
view axis, so the same view direction with up (0, +1, 0) produces the same
image. A geometry whose size or position ignores the projection's sign
renders differently through the two.
An ordinary +90° camera that sees exactly what buildCubeFaceCamera sees: the −90 fov negates both NDC axes, which is a 180° roll about the view axis, so the same view direction with up (0, +1, 0) produces the same image. A geometry whose size or position ignores the projection's sign renders differently through the two.