Title: Visualizing 3D
1Visualizing 3D
- Between Measurement and Illusion
- Dan Collins
- VizProto
2- Visualization is.
-
- Visualization is a method of computing. It
transforms the symbolic into the geometric,
enabling researchers to observe their simulations
and computations. Visualization offers a method
for seeing the unseen. It enriches the process of
scientific discovery and fosters profound and
unexpected insights. In many fields it is already
revolutionizing the way scientists do science. -
- SIGGRAPH proceedings, 1987. B. McCormick, T.
DeFanti, and M. Brown MCC87
3Euclid300 B.C.
- Euclid's "Elements," written about 300 B.C., a
comprehensive treatise on geometry, proportions,
and the theory of numbers, is the most long-lived
of all mathematical works. This manuscript
preserves an early version of the text. Shown
here is Book I Proposition 47, the Pythagorean
Theorem the square on the hypotenuse of a right
triangle is equal to the sum of the squares on
the sides. This is a famous and important theorem
that receives many notes in the manuscript.
4Euclids description of the Pythagorean theorem
5Euclid300 B.C.
- Euclid also wrote Optica, the first text on
geometrical optics, in which he defines the terms
visual ray and visual cone. - He noted that light travels in straight lines and
described the law of reflection. He believed that
vision involves rays going from the eyes to the
object seen and he studied the relationship
between the apparent sizes of objects and the
angles in which they meet at the eye.
Raphael, The School of Athens, 1509, Fresco,
Vatican, Rome
Detail showing Euclid with his students
6Pythagorus580-520 B.C.
- Pythagorus was a mathematician who made
important contributions to geometry. "He was a
Greek philosopher and religious leader who was
responsible for important developments in the
areas of mathematics, astronomy, and music
theory. He was also a healer, a wrestler, and was
politically active. He founded a philosophical
and religious school which has come to be known
as the Pythagorean Society. - The Pythagoreans saw that many things in the
universe were related in ways that could be
stated in numbers. They reasoned that numbers
must be the 'stuff' philosophers were looking
for. The universe including man is a closed
system. Both can be understood by the relation of
the parts. These relations can be expressed in
terms of numbers. These ideas led them to believe
that if one could penetrate the secrets of
numbers, he would penetrate the secrets of the
universe and the destiny of man. This led to the
careful study of geometry, the highest form of
mathematics.
7PantheonRome, Italy, 118 to 126 ADArchitect
unknown
Exterior view of the Pantheon in modern day Rome
Interior view of the Pantheon Giovanni Paolo
Panini, c. 1750
8The Pantheon and the Neo-Pythagoreans
- The Roman pantheon can be considered an
architectural image of the Greek Pythagorean
cosmos, a "living organism" with a
mathematically-proportioning "soul" and
unchanging, "eternal" consonant-symphonic ratios.
To generate harmony, the laws of arithmetic,
geometry, astronomy and musical-proportions are
fused. It "resembles the heavens", but is a
resemblance based on mathematical knowledge, a
summary of the ancient quadrivium. -
- --Girt Sperling
- The quadrivium was the higher division of the
seven liberal arts in the Middle Ages, composed
of geometry, astronomy, arithmetic, and music.
Section showing pythagorean ratios at work in the
Pantheon.
9Before Perspective
- Perspectival errors appear in paintings usually
done before 1400. - The perspective lines usually converge, but not
to a single point and not on the horizon. - Initial word panel of Psalm from the Kaufmann
Haggadah. Spain, late 14th C.
10Brunelleschi1377-1446
- Brunelleschi designed the stupendous dome which
crowns the cathedral in Florence, a work which
occupied him intermittently from 1417 to 1434.
The technical difficulties involved in erecting
the new dome underscore an important aspect of
his talents he was a daring innovator, with a
solid knowledge of math and mechanics.
11Brunelleschi
- He developed many important construction methods
as well as contributing to the evolution of
perspective. His mathematical work led to the
invention of linear perspective.
12Brunelleschi
- Filippo Brunelleschi was the first to carry out a
series of optical experiments that led to a
mathematical theory of perspective.. Brunelleschi
used his training as a gold smith to apply a
silver background on a painted panel, allowing
the color of the sky and passing clouds to become
part of the painting as seen by the viewer. This
was an attempt at a perspective painting and
interactive art. The panel was constructed with a
hole at the vanishing point. The reflection of
the image was viewed in a mirror through the
hole, giving an illusion of depth. - http//library.thinkquest.org/3257/illusion.htmlp
eep -
-
13Brunelleschi devised a method of perspective for
architectural purposes he is said by Manetti to
have made a ground plan for the Church of Santo
Spirito in Florence on the basis of which he
produced a perspective drawing to show his
clients how it would look after it was built.
14Masaccio1401-1428
- Masaccio's Trinity, 1427-28 Santa Maria Novella,
Florence (6.67 x 3.17 m) is often used to
illustrate the early culmination of mathematical
perspective experiments.
15Alberti1404 - 1472
- ALBERTI'S WINDOW
- The traditional form of pictorial representation
using perspective methods developed by
Renaissance artists is sometimes referred to as
Alberti's Window. - This is because, in his treatise Della pittura,
On Painting, 1435-6, the Classical theorist and
painter Leon Battista Alberti noted that, when he
set out to paint a scene on a panel, he assumed
the picture would represent the visible world as
if he were looking through a window. Some artists
did, in fact, create grids across the opening of
a window and transfer the scene to a gridded
canvas as compelling evidence that western
perspective was a natural form of representation.
Albertis fenestre (window) or velo
16Alberti
- Alberti's Construction System
-
- 1. B-one braccio module (one third of the height
of a man). The base of the picture is divided
into braccia. The height of the man at the front
plane of the picture gives the level of the
horizon, H. - 2. The braccio divisions are joined to the
perspective focus, V, to give the orthogonals. - 3. In side elevation, lines are drawn from
braccio divisions behind the picture plane P to
the eye at E. The points of intersection on P are
noted. - 4.The levels of the points of intersection are
marked at the side of the picture plane, and
locate the horizontal divisions of the tiles. Z
is the 'distance' point, though Alberti only
mentions using one diagonal to check the
construction.
17Paolo Uccello
- Among the best examples of early uses of linear
perspective is Paolo Uccello's fresco of the
"Deluge" in Florence, completed about 1448. Here
linear perspective is used to present an
elaborate architectural setting. The real object
of fascination, however, is Uccello's rendering
of the mazzocchi, the curious checkered hats, of
which there are two in "The Deluge. Ucello had
actually drawn such wonderful polyhedral forms in
studies of perspective drawings, and these
clearly demonstrate the mastery he had of the new
mathematical techniques.
18Piero della Francescac.1420 - 1492
- The culmination of the mathematical theory of
perspective with a philosophical program of the
most intense and religious order comes with the
work of Piero della Francesca. His St. Anthony's
Polyptich, in Perrugia, shows how masterfully he
was able to use the new theory of perspective.
19Leonardo1452 - 1519
- Perspective is nothing else than the seeing of an
object through a sheet of glass, on the surface
of which may be marked all the things that are
behind the glass --Leonardo da Vinci - Leonardo studied optics from both the scienitific
and the artistic points of view. He believed that
painting should be considered a Liberal Art
because it was based on mathematically derived
perspective theory and satisfied the primary
sense of sight. Da Vinci realized that unless a
person viewed a painting through a peephole, the
visual image would be different than the image
the artist painted.
20Dürer1471-1528
- One of several machines invented by Dürer for
making perspectival drawings consisted of a
needle driven into the wall and a piece of string
and a hinged frame. The piece of string has a
pin on one end and a weight on the other between
the eye of the needle and the object is placed a
wooden frame within which every point can be
determined by two movable threads crossing each
other at right angles. When the pin is put on a
certain point of the object the place where the
string passes through the frame determines the
location of that point within the future picture.
This point is fixed by adjusting the two movable
threads and is at once entered upon a piece of
paper hinged to the frame and by a repetition of
this process the whole object may be transferred
gradually to the drawing sheet.
A woodcut from Albrecht Dürer's treatise on
measurement Underweysung der Messung, 1527
21Dürer1471-1528
- The Perspectograph is an instrument that allows
the user to obtain, point by point, a correct
perspective drawing of a three dimensional
object. Perspectographs were used by painters and
sceno-graphers in 16th and 17th cent. (and as
early as the 15th cent. by Alberti). Some types
of Perpespectograph are very simple (as these
reproduced in Dürer's xylographies), some types
are rather complex. In this model of Dürer's
perspectograph, an observer looking through the
ocular sees the pattern drawn on the vertical
table exactly superimposed on the pattern drawn
on the horizontal table.
Dürer's Perspectograph, early 16th c. (replica)
22Palladio1508-1580
- The art historian Rudolph Wittkower writes, "The
conviction that architecture is a science, and
that each part of a building, inside as well as
outside, has to be integrated into one and the
same system of mathematical ratios, may be called
the basic axiom of Renaissance architects." Many
modern authors have analyzed Wittkower's thesis
that harmonic proportions derived from musical
scales played a central role in the minds and
designs of Renaissance theorists and architects.
Central to this debate is Palladio's oeuvre--his
architecture and his Quattro libri (four books). - --Stephen R. Wassell
Elevation and plan of a typical Palladian villa.
23vitruvius c. 90-20 B.C.E.
- Images by Cesare Cesariano (1521)
- This is a profusely illustrated edition of the
most famous of antique texts on architecture, The
Ten Books on Architecture. It was known
throughout the Middle Ages, in multiple copies
and probably versions.
24Hans Holbein, The Ambassadors, 1536
25(No Transcript)
26Francesco Borromini 1599 - 1667
This architectural tromp l'oeil of an actual
"perspective" collonade in the Palazzo Spada, was
fashioned by Galileo's contemporary, Borromini in
1653. This is actually an illusion, played with
the help of mathematical perspective. The trick
is revealed in the image at the right where two
figures of equal height show the perspective at
work. The image in the center is a modern CAD
rendering.
27Diderot 1713 - 1784
- Denis Diderot was the creator of the first
Encyclopedia in 1751. More then 160 authors
contributed to the encyclopedia. By 1789 there
were nearly 16,000 copies sold. The pope placed
the encyclopedia on the Index of Prohibited
books. - In his discussions on art, he provides the
broader social context for the arts. In his
entries on Art, he describes the origin of the
sciences and arts, their distribution into
liberal and mechanical arts, the goal of the
arts, and his own project for a general treatise
on the mechanical arts. - We began by making observations on the nature,
service, usage, qualities of beings of their
symbols then we gave the name of science or of
art or of discipline in general, to the center or
unifying point to which we related the
observations that we had made, to form a system
of either rules or instruments, of rules
tending towards the same goal because that is
what a discipline is in general. (ART, in Diderot
d'Alembert, 1751-1772, Vol. 1, p. 713)
28Contour plot . Map of Paris by L. L. Vauthier
(1874), showing population density by contour
lines, the first statistical use of a contour
map. This approach to representing multivariate
data arose from the use of contour maps in
physical geography showing surface elevation
(first published in 1752 by Buache), which became
common in the early 19th century. It was not
until 1843, however, that this idea was applied
to data, when Léon Lalanne constructed the first
contour plot, showing the mean temperature, by
hour of the day and by month at Halle (lower
left). Lalanne's data formed a regularly-spaced
grid, and it was fairly easy to determine the
isolines of constant temperature. Vauthier
generalized the idea to three-way data with
arbitrary (x,y) values in his map of the
population density of Paris. http//www.math.york
u.ca/SCS/Gallery/ noframes.html
29This figure (showing the population of Sweden
from 1750-1875 by age groups) by Luigi Perozzo,
from the Annali di Statistica, 1880, is a very
early example of a 3D stereogram. Perozzo's
figure is also notable for being printed in color
in a statistics journal, and in a way which
enhances the perception of depth.
30Etienne-Jules Marey1830- 1906
Etienne-Jules Marey, 1830-1906, was among the
pioneers of dynamic graphics and the graphical
representation of movement and dynamic phenomena.
This image, from Marey's La méthode graphique
dans les sciences experimentales (1876, p. 150)
compares the time course of respiration of a
person at rest and under exertion, using a
pen-recording device to plot the traces over
time.
31Mapping the London Underground
-
- Harry Beck's 1933 diagram of the 7 lines of the
London Underground, although geographically
inaccurate, provides a coherent overview of a
complex system. (See map at upper left). - With excellent color printing, classic British
railroad typography (by Edward Johnson), and, in
the modern style, only horizontal, vertical, and
45 degree lines, the map became a beautiful
organizing image of London. - For apparently quite a number of people, the map
organized London (rather than London organizing
the map). Despite 70 years of revision due to
extensions of the Underground and bureaucratic
tinkering (the marketing department wrecked the
map for several years), the map nicely survives
to this day. -
- Compare map from late 1920s at lower left.
32The History of CAD
-
- 25 years ago, nearly every drawing produced in
the world was done with pencil or ink on paper.
Minor changes meant erasing and redrawing while
major changes often meant recreating the drawing
from the scratch. If a change to one drawing
affected other documents you were dependent upon
having someone manually recognize the need to
make the changes to the other drawings and to do
so. - CAD has fundamentally changed design and the
way we visualize 3D.
33Dynamic Visualization
-
- Visualization of Storm patterns combines 3D
graphics and actual metrics
34Visualizing the Web Gunilla Elam,Warriors of
the Net, 1999
-
- Elams background is in fine arts and she also
did research into the social aspects of computing
and networking technologies at the Ericsson
Medialab and now works as a designer at a startup
venture called AirClic. Of the many challenges in
making Warriors of the Net, Elam says that, The
hardest part was without question to simplify the
structure into an understandable, easy to grasp
concept. I had not been going into the tech part
of the Internet much before starting with this,
so the way we did it was Tomas filling me up with
as much information I could handle, then let me
think about it for a while and melt it down to a
level where anyone would be able to understand
it.
35Decision Theater at ASU
-
- East Valley Water Forum (EVWF)
- The EVWF is a regional cooperative of water
providers who are working with Arizona Department
of Water Resources (ADWR) with support from the
Bureau of Reclamation to develop data driven
scenarios about ground water policy issues under
a variety of drought scenarios. Their work with
the Decision Theater will assist them in
developing informed planning decisions as the
east portion of the Salt River Valley continues
its explosive growth. Key collaborators K.
Sorenson (City of Mesa) and D. Mason (ADWR).
36Decision Theater at ASU
-
- Urban Heat Island (UHI)
- The UHI explores and models heat retention in the
Phoenix metropolitan area. The effect of UHI
during Arizona summers has been a 12 degree rise
in night time low temperatures in the last 20
years. Scientists have developed predictive
models based on dynamic changes in land use that
can help planners and decision makers better
understand the UHI phenomenon. The goals are to
understand probable impacts of UHI on planning
urban systems (such as electrical capacity to
accommodate increased power use for air
conditioning) and to explore the effectiveness
and impact of potential solutions for mitigation.
37Decision Theater at ASU
-
- Environmental Fluid Dynamics Program
- Typically, computational fluid dynamics models of
atmospheric events are presented as numeric data
or 2 dimensional graphics. Data from a Defense
Threat Reduction Agency (DTRA) funded project to
simulate anthrax release in Oklahoma City has
been modeled and visualized as a 3D animation.
This work provides a foundation for developing
interactive scenarios to study the effects of
wind direction, wind speed, and building design
on dissemination of bacterial agents. The
research permits informed training of emergency
response teams to real natural or man made
emergencies.
38The History of CAD (pre-1970)
- The first graphic system was in mid 1950 the US
Air Force's SAGE (Semi Automatic Ground
Environment) air defense system. The system was
developed at MITs Lincoln Laboratory. The system
involved the use of CTR displays to show
computer-processed radar data and other
information. - In 1960, Ivan Sutherland used TX-2 computer
produced at MIT's Lincoln Laboratory to produce a
project called SKETCHPAD, which is considered the
first step to CAD industry. - In 1960 McDonnell Douglas Automation Company
(McAuto) founded. It will play a major role on
CAD developments. - The first Computer-Aided Design programs used
simple algorithms to display patterns of lines at
first in two dimensions, and then in 3-D. Early
work in this direction had been produced by Prof.
Charles Eastman at Carnegie-Mellon University,
the Building Description System is a library of
several hundred thousands architectural elements,
which can be assembled and drawn on screen into a
complete design concept. - In mid 1960 large computers characterized the
period, vector display terminals and software
development done in assembly language. The only
significant attempt to create a commercially CAD
system was Control Data Corporation's
Digigraphics division, a successor to the
previously mentioned ITEK. The system costs half
million dollars and were sold in few units. - In 1968 Donald Welbourn had the vision to see the
possibility of using computers to assist pattern
makers to solve the problems of modelling
difficult 3D shapes. Today we take for granted 3D
modelling, in 1968 only crude 2D drawing systems
were available using terminals linked to large
main frame computers. - David Evans and Ivan Sutherland founded in 1968
Evans and Sutherland. - In 1969 were founding Computervision and Applicon
companies. Computervision was created to produce
systems for production drafting and in the same
year it sold the first commercial CAD system to
Xerox.
39The History of CAD (1970-1980)
- At the end of 70s a typical CAD system was a
16-bit minicomputer with maximum of 512 Kb memory
and 20 to 300 Mb disk storage at a price of
125,000 USD.
40The History of CAD (1980-1990)
- 1981 Computer graphics from Cornell University
founded 3D/Eye Inc., a pioneered 3D and graphics
technology. Unigraphics introduced the first
solid modeling system, UniSolid. It was based on
PADL-2, and was sold as a stand-alone product to
Unigraphics. - 1982 CATIA Version 1 is announced as an add-on
product for 3D design, surface modeling and NC
programming. Mini computers with much more power
at less cost started to appear. This was a major
step forward and by 1984 the technology began to
be competitive with traditional methods. For many
years aircraft had of course been designed using
computers, but now it was becoming possible to
economically design saucepans and other domestic
products with complex 3D shapes using a computer.
Autodesk was founded by sixteen people in April
1982 in California by initiative of John Walker
in idea to create a CAD program for a price of
1000 to can run on PC. John Walker has been
running Marinchip Systems for two years before.
In November at COMDEX trade show in Las Vegas was
demonstrated the first CAD program in the world
that runs on PC. This was the initial release of
AutoCAD and deliveries begun in December. - 1983 Unigraphics II introduced to market
- 1984, a Hungarian physicist, Gabor Bajor,
smuggled two Macs into his country. At the time,
ownership of personal computers was illegal under
Communist rule. Using Pascal, he and a teenager,
Tamas Hajas worked to write a 3D CAD program for
the Mac which will be the beginning of Graphsoft
Company. Drafting capabilities are added to CATIA
in 1984, enabling it to function independently of
CADAM. The first Autodesk Training Centre. In
October AutoCAD version 2 (Release 5) with text
improvements, DXFIN and DXFOUT commands, new
Inquire commands, Object Snap, named views,
Isometric capabilities and new Attribute
features. - 1988 Surfware Inc., ships the first version of
SurfCAM, a CAD/CAM program. - 1989 Parametric Technology ships the first
version of Pro/ENGINEER.
41The History of CAD (1990-1995)
- 1990 McDonnell Douglas (now Boeing) chooses
Unigraphics as the corporate standard for
mechanical CAD/CAM/CAE. Autodesk ships Animator
Pro, a 2D painting and animation program for DOS.
By 1993 over 15,000 copies have been sold
worldwide. - 1991 Microsoft developed Open GL for use with
Windows NT. Open GL is an API procedural software
interface for producing 3D graphics and includes
approximate 120 commands to draw various
primitives such as points, lines, and polygons.
Also includes support for shading, texture
mapping, anti-aliasing, lighting and animation,
atmospheric effects such as fogging and
simulation of depth-of-field. Open GL, developed
by Silicon Graphics, is a standard for the 3D
color graphics programming and rendering. - 1992 Autodesk ships 3D Studio version 2 for DOS.
Autodesk ships AutoCAD Release 12 for DOS in
June. Includes AutoCAD SQL Extension
(ASE)/Autodesk SQL Interface (ASI) that lets you
establish links between AutoCAD and an SQL
database. Advanced Modeling Extension (AME)
release 2.1 is supported by Release 12, with
region modeling and new solid primitives. AutoCAD
Render is included with AutoCAD. - 1993 The first AutoCAD (Release 12) for Windows
platforms. It required 8 MB RAM and 34 MB Hard
Drive space for complete installation. The
Windows version of AutoCAD includes 36 icons
toolbox, allows multiple AutoCAD sessions,
separate Render window, support for Windows GUI,
DDE and OLE, as well as Drag-and-Drop and Bird's
Eye view capabilities. The AutoCAD main menu has
been eliminated After initial configuration,
AutoCAD displays the graphics screen. AutoCAD 12
for Windows was one of the most successful CAD
programs ever - 1994 MiniCAD version 5. Hewlett Packard ships
version 3.5 of PE/Solid Designer, its high end
Solid Modeling. - 50,000 seats installed to date.
- 1995 CATIA-CADAM AEC Plant Solutions are
announced. This next generation object-oriented
plant modeling system enables powerful
knowledge-based engineering capabilities that can
dramatically streamline the process of plant
design, construction and operation. It brings the
power of "smart" applications to the desktop with
next generation object-oriented modeling. IDEAS
Master Series version 2.1 from SDRC. Mazda Motors
Corp. will install 2,400 seats of this product.
Parametric Technology ships Pro/E version 15, the
first parametric modeling CAD/CAM program and the
first high-end 3D solid modeling package
available on NT platforms.
42The History of CAD (1996-99)
- 1996 Solid Edge version 3 from Intergraph hits
the market at the price of around USD 6000.
SolidWorks Co. ships Solid Works, an ambitious 3D
package based on Parasolids modeling Kernel. It
comes with a good complex surface modeling and a
good graphical user interface. 3D/EYE Inc., ships
Tri Spectives Technical version 2, a modeling,
illustration and animation program for Windows
platforms, at a very low price. Lightscape
version 3, a high-end rendering and animation
package, comes with IES photo-metric data
capabilities. IES (Illuminating Engineers
Society) is the industry standard for describing
the shape and intensity of light energy
distribution froma light source, ray tracing,
natural light according to location and
orientation of the building. Lightwave 3D version
5 and 5.5 from New Tek, a high-end rendering,
modeling and animation program. AutoCAD LT 95.
Diehl Graphsoft released MiniCAD 6 for Windows,
the first cross-platform version of MiniCAD.
Pro/E version 17 with a new module which allows
files to be exported into VRML file format for
display on the Internet. - 1997 Autodesk ships 3D Studio MAX release 2 and
a cut-down version called 3D Studio Viz. EDS
introduces a number of new industry-leading
capabilities with its new version of Unigraphics,
including WAVE - which will enable the
definition, control and evaluation of product
templates - considered the most important new
technology affecting the CAD/CAM/CAE industry in
the next five years. First version of IDEAS
Artisan Series from SDRC, fully compatible with
Master Series, priced at USD 5,000. Form Z, a
solid and surface modeler, first available only
for Mac platforms, debuts on Windows market. - 1998 Autodesk Architectural Desktop - integrated
architectural solution based on AutoCAD 14. First
version of IronCAD for VDS market. Autodesk ships
3D Studio MAX version 2.5 Lightwave 3D version
5.6 from New Tek, comes with Procedural shades
for snow, water and rust, Stereoscopic rendering,
SkiTracer image warping for real time
visualization of generated sky, and more. Solid
Edge version 3 from Intergraph with more than 150
new features. Solid Works 98 adds 150 new
capabilities. - 1999 CATIA Version 5 for native Windows NT and
UNIX. Lightwave 3D version 6 from New Tek. Think3
entry in the CAD market with thinkdesign, the
first mechanical design software product to offer
the power of parametric solids, advanced
surfacing, wireframe and 2-D drafting, all in one
environment. VectorWorks replaces MiniCAD. 3D
Studio MAX cumulus 29 of the entire 3D-animation
market and 38 of the 3D PC markets.
43From Euclid to Desargues
- Euclid's Optica, c. 300 B.C., was the first text
on geometrical optics, in which are defined the
terms visual ray and visual cone. - Vitruvius' Ten Books on Architecture which
appeared about 25 B.C., was the only book on
architecture to survive from antiquity. It
profoundly influenced Renaissance architecture
and thinking, including that of Alberti, who
quoted Vitruvius in his Della pittura. Vitruvius
wrote Perspective is the method of sketching a
front with the sides withdrawing into the
background, the lines all meeting in the center
of a circle. Unfortunately he didn't elaborate on
that. Elsehere, Vitruvius' reference to Greek and
Roman stage design, implied an understanding of
the vanishing point. - Ptolemy's Optica, c. 140 A.D., was another early
text on geometrical optics, and included theories
on refraction. The centric ray is defined by
Ptolemy as the ray that does not get refracted.
The centric ray, we'll see, is important in the
theory of perspective. In his Geographia, c. 140
A.D., Ptolemy applies the principles of geometric
optics to the projection of the spherical surface
of the earth onto a flat surface, to produce a
map. He is said to have made the first known
linear perspective construction for drawing a map
of the world. Ptolemy apparently knew about
perspective, but applied it only to maps and to
stage designs. - Galen's De usu partium, c. 175 A.D., contains an
early but erroneous description of how the eye
creates images. The book was still important,
however, as a stepping stone in the development
of the theory of perspective. - From Islam, Alhazen's Perspectiva, c. 1000 A.D.,
was an important compendium on optics. It
integrated the works of Euclid, Ptolemy, and
Galen. - Roger Bacon's Opus Majus, c. 1260 A.D., included
a section on optics, whose geometric laws, he
maintained, reflected God's manner of spreading
His grace throughout the universe. - John Pecham's Perspectiva communis, c. 1270 A.D.,
was another treatise on optics that was widely
available during the Renaissance. - Blasius of Parma's Quaestiones perspectivae, c.
1390 A.D., was a popular adaptation of the works
of Bacon and Pecham.
44From Euclid to Desargues
- We are all familiar with Euclidean geometry and
with the fact that it describes our
three-dimensional world so well. In Euclidean
geometry, the sides of objects have lengths,
intersecting lines determine angles between them,
and two lines are said to be parallel if they lie
in the same plane and never meet. Moreover, these
properties do not change when the Euclidean
transformations (translation and rotation) are
applied. Since Euclidean geometry describes our
world so well, it is at first tempting to think
that it is the only type of geometry. (Indeed,
the word geometry means measurement of the
earth.) However, when we consider the imaging
process of a camera, it becomes clear that
Euclidean geometry is insufficient Lengths and
angles are no longer preserved, and parallel
lines may intersect. - Perspective is an example of the geometric
operation of projection and section where
projection lines from the outline of an object to
the eye are sectioned or cut by a picture plane.
This has roots in the conic sections, where
projection lines from a circle to a point form a
cone, which is then sectioned by a plane to give
a circle, ellipse, parabola, or hyperbola,
depending on the angle of the cutting plane.
These ideas were expanded by Gerard Desargues
(1593-1662), architect/engineer, into the branch
of mathematics called projective geometry. - Projective geometry is a branch of mathematics
that deals with the relationships between
geometric figures and the images, or mappings, of
them that result from projection. Common examples
of projections are the shadows cast by opaque
objects, motion pictures, and maps of the Earth's
surface. -
Projection of one line onto another
Central projection of one plane on another
45Frank Lloyd Wright
- Wright used nature as the basis of his
geometrical abstraction. His objective was to
conventionalize the geometry which he found in
Nature, and his method was to adopt the abstract
simplification which he found so well expressed
in the Japanese print. Therefore, it is not too
shocking perhaps that in this quest his work
should foreshadow the new mathematics of nature
first put forth by Benoit Mandelbrot fractal
geometry. - --Leonard K. Eaton
Floor plan from a late Wright residence.
46Platonic Solids
- The so-called Platonic Solids are regular
polyhedra. Polyhedra is a Greek word meaning
many faces. There are five of these, and they
are characterized by the fact that each face is a
regular polygon, that is, a straight-sided figure
with equal sides and equal angles. - The Greeks, who were inclined to see
mathematics as something of a religious truth,
found this business of there being exactly five
Platonic solids very compelling. The philosopher
Plato concluded that they must be the fundamental
building blocks the atoms of nature, and
assigned to them what he believed to be the
essential elements of the universe. He followed
the earlier philosopher Empedocles in assigning
fire to the tetrahedron, earth to the cube, air
to the octahedron, and water to the icosahedron.
To the dodecahedron Plato assigned the element
cosmos, reasoning that, since it was so different
from the others in virtue of its pentagonal
faces, it must be what the stars and planets are
made of. -
-
-
47references
- General Science and Art http//library.thinkques
t.org/3257/ - Digital Design Media http//www.gsd.harvard.edu/
malcolm/DDM/GALLERY/15.01_1956.gif - Durer http//www.newcastle.edu.au/department/fad
/fi/woodrow/durer-c.htm - General Information on Perspective
http//www.newcastle.edu.au/department/fad/fi/wood
row/an-persp.htm - Leonardo http//www.mos.org/sln/Leonardo/Leonardo
sPerspective.html - Alberti http//www.leonet.it/culture/nexus/98/Pa
squale.html - Pantheon http//www.leonet.it/culture/nexus/98/S
perling.html - Palladio (Stephen Wassell) http//www.leonet.it/
culture/nexus/98/Wassell.html - Brunelleschi http//www.cuny.edu/multimedia/arsn
ew/arch1.html