Difference between revisions of "Wallpaper Patterns"

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==Wallpaper Flow Chart==
 
==Wallpaper Flow Chart==
{{printable|wall-flow.pdf}}
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{{printable|[[wall-flow.pdf]]}}
 
It can be quite difficult to find and mark all symmetries of a wallpaper pattern.  However, it is possible to identify
 
It can be quite difficult to find and mark all symmetries of a wallpaper pattern.  However, it is possible to identify
 
the symmetry group of a wallpaper pattern without finding all of its symmetries by focusing on the most important features.
 
the symmetry group of a wallpaper pattern without finding all of its symmetries by focusing on the most important features.

Revision as of 03:25, 5 February 2007

Wallpaper catalog of Remondini - Bassano - Italy, 18th century

Suggested reading:

  • Visions of Symmetry, pg. 31-44, 77-78.

Relevant examples from Escher's work:

  • Escher's sketches of Polya's 17 wallpaper patterns. Visions of Symmetry, pg. 24-26.

Wallpaper Patterns

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Start learning about Wallpaper Patterns with the Wallpaper Exploration.

A wallpaper pattern is a plane figure which has more than one direction of translation symmetry. Most actual wallpaper fits the bill, because it must repeat left to right in order to hang in strips, and it must repeat vertically so that multiple strips can be cut from the same roll.

In a wallpaper pattern, the lattice of translations is the collection of all translated images of a point. To mark the lattice of translations, choose a point in the figure and then mark all translations of that point. Be careful not to mark reflected or rotated versions of the point.

The lattice is so named because connecting nearby dots with edges results in a grid, or lattice, structure. These lattice lines depend on which dots one chooses to connect, so they are not usually shown.

The Seventeen Wallpaper Groups

Construction.png This section is unfinished.

File:Test1.svg File:Test2.svg File:Test3.svg

Wallpaper Flow Chart

It can be quite difficult to find and mark all symmetries of a wallpaper pattern. However, it is possible to identify the symmetry group of a wallpaper pattern without finding all of its symmetries by focusing on the most important features. Following this flow chart is a quick way to identify symmetry groups of wallpaper patterns.

Escher's Use of Symmetry

Escher's Regular Division of the Plane Drawings served as source material for his finished printed works. The vast majority of these fall into one of seven symmetry groups: p1, p2, p3, p4, p6, pg, and pgg. These are exactly the symmetry groups which have no reflection symmetry - only translation, rotation, and glide reflection. If two creatures meet on a line of mirror symmetry, they must have a flat edge, and recognizable figures from life rarely have perfectly straight edges. Because of this, Escher mostly avoided mirror symmetry, although he did create a few drawings where bilateral symmetry of the motif leads to overall mirror symmetry of the pattern.

Some animal motifs, generally larger animals, are usually seen from the front or side, and so look silly when viewed upside down or at an angle. Escher's was careful, at least in his later work, to avoid symmetries containing rotation when working with such animals. On the other hand, Escher writes [1]:

When a rotation does take place, then the only animal motifs which are logically acceptable
are those which show their most characteristic image when seen from above.

For example, insects and lizards occur frequently in Escher's work when rotation symmetry is present.

Exercises

Wallpaper Exercises

Related Sites

Notes

  1. Visions of Symmetry, pg. 78