Prusinkiewicz, Lindenmayer - The algorithmic beauty of plants.pdf

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Aristid Lindenmayer 1925–1989
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Przemyslaw Prusinkiewicz
Aristid Lindenmayer
The Algorithmic Beauty
of Plants
With
James S. Hanan
F. David Fracchia
Deborah Fowler
MartinJ.M.deBoer
Lynn Mercer
With 150 Illustrations, 48 in Color
This edition of The Alogirthmic Beauty of Plants is the electronic version
of the book that was published by Springer-Verlag, New York, in 1990 and
reprinted in 1996. The electronic version has been produced using the orig-
inal L A T E X files and digital illustrations.
2004 Przemyslaw Prusinkiewicz
All rights reserved.
c
Front cover design: The roses in the foreground ( Roses by D. R. Fowler,
J. Hanan and P. Prusinkiewicz [1990]) were modeled using L-systems. Dis-
tributed ray-tracing with one extended light source was used to simulate
depth of field. The roses were placed on a background image (photgraphy
by G. Rossbach), which was scanned digitally and post-processed.
Preface
The beauty of plants has attracted the attention of mathematicians for Mathematics
and beauty
centuries. Conspicuous geometric features such as the bilateral sym-
metry of leaves, the rotational symmetry of flowers, and the helical
arrangements of scales in pine cones have been studied most exten-
sively. This focus is reflected in a quotation from Weyl [159, page 3],
“Beauty is bound up with symmetry.”
This book explores two other factors that organize plant structures
and therefore contribute to their beauty. The first is the elegance and
relative simplicity of developmental algorithms , that is, the rules which
describe plant development in time. The second is self-similarity ,char-
acterized by Mandelbrot [95, page 34] as follows:
When each piece of a shape is geometrically similar to the
whole, both the shape and the cascade that generate it are
called self-similar.
This corresponds with the biological phenomenon described by Herman,
Lindenmayer and Rozenberg [61]:
In many growth processes of living organisms, especially of
plants, regularly repeated appearances of certain multicel-
lular structures are readily noticeable.... In the case of a
compound leaf, for instance, some of the lobes (or leaflets),
which are parts of a leaf at an advanced stage, have the
same shape as the whole leaf has at an earlier stage.
Thus, self-similarity in plants is a result of developmental processes. Growth and
form
By emphasizing the relationship between growth and form, this book
follows a long tradition in biology. D’Arcy Thompson [143] traces its
origins to the late seventeenth century, and comments:
Organic form itself is found, mathematically speaking, to be
a function of time.... We might call the form of an organism
an event in space-time , and not merely a configuration in
space .
This concept is echoed by Halle, Oldeman and Tomlinson [58]:
The idea of the form implicitly contains also the history of
such a form.
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