…Secondly, the outline should be as characteristic as possible. It should clearly identify the nature of the object; preferably the silhouette should be so striking that the object can be recognized even without any detail, which always has an disturbing effect on the figure as a unit… and .… The most usual shapes are those of living creatures. However, for animals the question immediately arises, from what angle should they be viewed so that their silhouettes are as characteristic as possible? Quadruped animals are usually most easily recognised when viewed from the side, while reptiles and insects appear most typical from above and the human form is most characteristic from the front.
However, although the above is indeed relevant, and indeed I concur with all its sentiments, these few sentences were as detailed as Escher gave of his thoughts on the matter. Although this may be said to have the benefit of succinctness, in matters of understanding the issue, it is far too cursory, lacking in detail and any illustration. Such matters require a more thorough, in-depth approach as regards the various intricacies than the brief offerings Escher has given us. Therefore, below I discuss this in more detail, firstly in a generalised sense, based upon Escher's statements, repeating relevant Escher quotes above, followed by a more in-depth discussion, liberally accompanied by illustrations, of my own views on the matter. Furthermore, for demonstrative purposes examples are shown, redrawn from other people's tessellations, of motifs that simply are of an inferior standard.
The illustrations below show these aspects in 'two-motif' units, with a line drawing of a actual motif, additionally shown as a silhouette to the immediate right. This is for the purpose of recognising the motifs outline immediately, without any 'distractions' of finer detail. The purpose of this is to see if the motif can be discerned by its silhouette alone.
Escher generalities: …In addition, it [a bird] has a characteristic shape, from above and below, from the front and the side.
Typical Representation
Firstly, birds are somewhat unusual in that their typical representation can be shown in a variety of ways, which partly explains their suitability for tessellation purposes. As such, they can be portrayed in flight, either from above, sideways or below, with the wings shown up, down or parallel, or perched on the ground. All are readily identifiable. However, ideally, birds should be portrayed in flight rather than alighted on the ground. By so doing, all the 'elements' that make up a bird, such as the head, body, wing and tail will be thus seen as individual elements. In contrast, when grounded or perched, the wings, the most typical feature of this motif, are folded, of which the silhouette is then not quite so readily recognisable.
Concerning the portrayal of flight, although the bird can be seen from numerous orientations and angles, it will be found that essentially there are only three basic positions. All of these are as good as the other as regards typical representation:
Both wings in a up position, left
Both wings in a down position, centre
Both wings in a outstretched position, right
Furthermore, the drawing of the birds' interior, of the head and wings has variations as regards the detail, to be discussed in a forthcoming essay.
A point to note concerning the anatomy, is that it is impossible for the wings to appear in 'one up and one down' positions - the wings act as a unit. i.e. both 'up' ,'down' or 'outstretched'. To portray the bird in this manner would be incorrect. The illustrations above show these three positions as a 'two-bird' unit, with a line drawing of a actual bird, additionally shown as a silhouette. This is for the purpose of recognising the birds outline immediately, without any 'distractions' of finer detail. From this, each of these is thus immediately recognisable as a bird at-a-glance.
Atypical Representation
An atypical representation would be to show the bird either 'full-on' or from the rear when perched. Both of these views would not show the most important element, the wings, and so consequently the silhouette would be less identifiable.
Fish
Escher generalities :… A fish is almost equally suitable; its silhouette can be used when viewed from any direction but the front.
Escher generalities:… the human form is most characteristic when seen from the front .
(No Escher generalities)
Another 'typical representation' is offered by the possibility of showing the dog in a sitting position. Although all the elements as detailed above are not so readily visible, enough of these remain to render the silhouette as unmistakably of a dog.
Yet another position commonly to be found is when the dog is lying down. However here, in contrast to the above poses, this aspect is lacking in showing the elements, as all the elements 'merge', as shown below. Although in the line drawing a dog is readily discernable, in silhouette a essentially formless shape occurs - if asked what this is, a dog would not be identifiable.
Atypical Representation
In contrast, alternative views, the 'head-on' or rear view, are not so discernable, as the elements will also 'merge'. For instance, with 'head-on', the tail would not be visible, as would the length of the body. Also, distinguishing features of the head would not be so apparent, such as the muzzle in profile. When viewed from the rear, only the back of the head would be seen, with the body being omitted. This obviously lacks the more typical outline of a profile view. Consequently, such aspects make a dog more difficult to recognise in silhouette in these portrayals.
Furthermore, if the outline is recognisable by a certain breed of dog rather than a generic one, then this is the indication of a tessellation of the highest ranking. (However, such a desire is most difficult in practise, as dogs are a most difficult creature to use for tessellation purposes. Indeed, even the accomplishment of a generic dog is cause for praise.)
Insects
Escher generalities: … insects appear most typical from above …
Typical Representation
Insects are best portrayed as when seen from above, from which the outline is thus obvious. From this, its 'elements', of head, body, wings, abdomen, legs and antenna are all immediately identifiable. The most notable feature of an insect is that of its intrinsic small size, of which when it has alighted on a object is thus more typically viewed as from above, and therefore this type of creature is thus more instantly recognisable as when so represented in this way.
Quadrupeds are indeed more easily recognisable when viewed from the side, as the disparate diagrams below illustrate. Essentially, when seen from the side, neglecting scale matters, one quadruped is very much like another. Consequently, it will be found that this can be of benefit when composing motifs, as for instance a dog that is not quite right may then be transformed into, say, a cat. Although other viewpoints are possible, such as 'head on' or as seen from the rear, these are not the best for silhouette purposes. For example, when seen from the side, the creatures head, body, legs and tail (if applicable) will all clearly be discernable. In contrast, if viewed head-on or from the rear, these elements would not be so distinct. For example, the head will merge into the body, and the body length will not be apparent. Another untypical viewpoint would be when the quadruped is lying down or sleeping. This is because its legs and tail (if applicable) would be tucked into the body, essentially merging if seen in silhouette. Consequently, these elements would not be seen on the silhouette, therefore rendering the creature less recognisable. In contrast, where a sitting position is shown in profile, this is more acceptable, as all the elements remain on view.
Some quadrupeds have different breeds, of which if by outline alone the type is thus recognisable then this adds to the inherent quality of the tessellation. For example, say of dogs, if a St. Bernard can be recognised, then this is thus better than a generic dog, all things being equal in terms of inherent quality of the two types of dog.
Created: 24 January 2006 (substantial extra material). Last updated: 25 August 2009. Minor revision: 9 August 2010. Changed wording, 'untipical' replaced by 'atypical'
Agree/disagree? E-me.