XY is the imageplane. The Zaxis represents the direction in depth. All 3D shapes are recovered from the image on the imageplane. The aspectratios of these 3D shapes are different and they vary with the change of the slant of the symmetryplane. In this animation, the slant of the symmetryplane is varied from 24° to 55°. When the slant is close to 90° or 0°, the aspectratio of the 3D shapes recovered ranges from zero to infinity.
