A lack of the use of arcs has mainly been the product of laziness on the part of the
animator. In traditional 2D animation, assistant animators find that it is much harder to
interpret the in-betweens on a curved path of action rather than in a straight line, as
conventional in-betweens would suggest. Similarly, lazy 3D animators prefer to let the
computer software decide the direction and placement of the in-betweens-which will
be automatically straight and predictable-rather than go in and adjust each one of the
in-between positions to enable the action to move more on the curve of an arc.