Fig. 4. Three-dimensional (3-D) reconstruction of the four wings of the flight dragonfly. (A) An original digital image of a dragonfly, and its 3-D reconstruction observed from the same perspective (overhead view). (B) The 3-D reconstruction observed from different viewpoints, represented by two parameters, azimuth or horizontal rotation (as AZ) and vertical elevation (as EL), both in degrees. AZ is positive as the viewpoint is rotated clockwise, while positive values of elevation correspond to movement above the object. Notice that the three orthogonal short arrows represent the body-centered coordinate system.