SPACING: 2D Animation principle

17 December, 2008

SPACING: 2D Animation principle

It is the allocation and
placing of the inbetweens. The combination of timing and spacing determines the
pace of action of any movement.


Spacing of drawing – general

When any object in nature moves
from a rest point X and stops at a point Y, it has a tendency, owning to the
properties of matter, to accelerate in a maximum speed in the middle of the
movement and then slow down to a stop. Obviously there are an infinite number of
variations in details, but this is the general tendency. A piston going to and
fro moves more slowly at the ends of its movement and so in animation the
drawings are closer together at the ends of the movement than in the middle.
This kind of movement is called simple harmonic motion and can be circumference
of a circle onto a straight line.

In animation, it is sometimes
difficult to graduate the space between drawings in this way and so usually an
approximation is made by halving, re-halving and halving again the distance to
be traveled, according to the time available. In some cases distances are split
for convenience into thirds or even quarters, although other proportions are
usually impracticable.

A human figure moving to and
fro, sawing for example moves in a similar way to a piston. The body weight
moves forwards, slows down, changes direction and starts to move backwards,
slows down, changes direction, starts to move forwards, and so on. The general
weight of the body moves forwards and backwards and the drawings are therefore
spaced in the same way as those for a piston. The space of the drawings of the
arm and saw are different from that action of sawing requires manipulation of
weight and muscles power.

Spacing of drawings in
perspective animation:

To animate in true perspective
requires complex draughts-man ship and some understanding of the geometrical
treatment of the subject.

Especially when a character
walks in perspective, an accurate perspective grid must be drawn giving the
height of the character and the length of the strides, so that the animator has
a clear idea of how the spacing gradually increases or decreases. It is quite a
difficult animation problem to make all parts of a figure get larger or smaller
and yet remain in the right proportions

For dramatic effect when a
character rushes towards on away from the camera, a low horizon is perfectible.
High horizons provide a more relaxed effect. In both instances the vanishing
point must be established in relationship with the horizon, which represents the
camera or the audience’s eye level. The increasing or decreasing lengths of
strides must be worked out by defining measuring points for every few drawings.
Estimation is possible, but must be plotted out carefully.

Lowering the horizon and
changing the vanishing point during animation can achieve variation in
perspective. This, however, requires some experience. Weight must be evident in
all perspective animation. In a perspective shot, a character can run from the
foreground ever the horizon in a few frames, approximately 12 to 16, provided
the right degree of anticipation is provided. Because of the speed of the action
it is better to use single frame animation.

Effective animation requires
movement in space and an illusion of three dimensions; otherwise the character
may appear to be too flat. Take advantage where possible of opportunities for
movement in exaggerated perspective. For instance, if some part of a figure or
object swings round close to the camera, emphasize the increase in size in the


Strobing is an effect that is
an integral part of the mechanism of the cinema indeed the stroboscope, invented
in 1832, was the first device used to present the illusion of a moving picture.
The reflections of images on a spinning disc were viewed through slits around
the edge of the disc so that a series of static images were seen in quick succession. A similar device, using the same
principle, was the zoetrope in which paper strips were viewed through slits in a
rotating cylinder. Strobing is liable to occur in the movement of an object,
which has a number of equally spaced, similar elements. Some examples are the
rungs of a ladder or the spokes of a wheel.

If a drawing of a ladder has
rungs drawn line apart and the ladder starts to move along its length of an
increasing speed, all is well until the amount of movement on the ladder is just
under ½in. At this point the rungs begin to flicker and when the ladder moves up
exactly 1in per frame, the movement is completely confused. This is because the
eye sees a set of rungs on one frame and the next frame it sees a set of rungs
half away between those on the first frame and does not know whether the
original rungs have moved to the right or to the left. On the next frame again,
the rungs on the first frame have moved along 1in and so are superimposed over
the rungs on the first frame.  This gives the impression that the rungs are
flickers on and off on alternate frames. If the movement is more than 1in, say
0.7in to the right, the eye jumps across the shorter gap and the rungs appear to
move 0.3in to the left. This is the reason for the well-known illusion of
stagecoach wheels appearing to turn backwards.

The best cure for this strobing
effect is to avoid situations where it may occur. The spoke of a wheel should be
as widely spaced as possible. One time honored solution is to have one broken
spoke so that the gap can be seen rotating. Another way of overcoming this
problem is to show the rim of the wheel rotating, but depict the spokes
themselves as whizzing round with a dry brush effect.

A wheel or ladder always
animates comfortably in the direction required if it moves by up to the distance
between one spoke, or rung and the next. At faster speeds, if the broken rung
dodges does not work, either avoid the sequence altogether, or work on it with
dry brush to suggest the speed at which it is going.

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One Response to SPACING: 2D Animation principle

  1. rakesh
    20 September, 2012 at 7:01 am


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