PERSONALIZED
PERSPECTIVES
IN
3-D
ASSEMBLY
By
Lawrence
S.B.
Massachusetts
Scarritt
Stead
Institute
1975
of Technology
Submitted in Partial
Fulfillment
of the Requirements for the
Degree of
Master of Science
at the
MASSACHUSETTS
INSTITUTE
OF
TECHNOLOGY
June 1978
Signature
of Author
Department of
Certified
by
Architecture
June 19,
1978
___________
Associate Professor
Nicholas Negroponte
of Computer Graphics
Thesis Supervisor
Accepted by
Professor
N.
John Habraken
Departmental Committee for Graduate Students
@
M.I.T. June
1978
The
work
reported herein was sponsored by the Office
Naval Research, Contract Number N00014-75-C-0460.
-1-
MASSACHUSETTS INSTITUTE
OF TECHNOLOGY
AUG 1 0 1978
LIBRARIES
of
MITLibraries
Services
Document
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http://libraries.mit.edu/docs
DISCLAIMER NOTICE
The accompanying media item for this thesis is available in the
MIT Libraries or Institute Archives.
Thank you.
Personalized Perspectives in 3-D Assembly
Table
Pag
of Contents
Abstract
3
Chapter One:
1.1
1.2
The Maintenance Problem
Raster Scan Computer Displays
Chapter Two:
2.1
2.2
2.3
Personalized Perspectives
3-D Display Techniques
Introduction
Vector 3-D
2.2.1
Z Intensity
Depth Cueing
Hidden Line Removal
2.2.2
Raster Scan 3-D
2.3.1
Hidden Surfaces without
Light Source Shading
2.3.2
Hidden Surfaces with
Light Source Shading
Hidden Surfaces with
2.3.3
Shading and Shadows
Chapter Three:
3.1
3.2
4
7
11
13
15
16
17
19
20
21
SOMA Puzzle Animation
The SOMA Puzzle
Animation Techniques
22
24
Appendix
26
References
35
Acknowledgements
36
-
2 -
Personalized Perspectives
in 3-D Assembly
By
Lawrence Scarritt
Stead
submitted to the Department of Architecture on June 19,
1978 in partial fulfillment of the requirements for the
degree of Master of Science.
Abstract
This
thesis
aims
to
establish
some
basic
tools
for
investigating
people's
ability
to interpret
various types
of renderings of 3-D solids,
and how a rendition aids or
inhibts visualization and "visual problem solving". Image
is
performed by a powerful computer graphics
generation
facility,
versatile
enough to permit several different
display schemes to be implemented and evaluated.
which supports
purpose
system
was
created
A
general
frames and animated
of
both single
generation
flexible
Objects are given colors and located in space
sequences.
by
a
simple
"script".
This script can then be used to
style
for
in
each
3-D
representation
make
images
comparison.
The
system's
capability
is
used to create
animated 3-D
sequences
showing
the
assembly of a multi block puzzle
into
a
cohesive figure.
It is a demonstration aimed at
raising
visualization
issues
pertaining
to 3-D assembly
tasks.
A
color
videotape
of
the
assembly using the
planned.
implemented display techniques is
Thesis
Supervisor:_____________
Nicholas Negroponte
Title:
Professor of Computer Graphics
Associate
-
3 -
CHAPTER ONE
Personalized Perspectives
The Maintenance Problem
1.1
It
sign
a
is
digital
computer,
in
partner
in
essential
these
challenges.
which
computers
its various
to
We believe that
will
be
soon
has
guises,
effort
any
goals and
the
that
are so complex
society
contemporary
of
tasks
many of the
our times that
of
become
manage
sucessfully
field in
yet another
involved
intimately
an
is
repair and maintenance of sophisticated equipment.
of the
State
the
between
specialized
given
extremely
to
be
computer
shooting
team
difficult
addressed,
and repair
Phd's),
of
at
Although
we
and
ultimately
aiding the
tasks.
-
4
-
knowledge
about
time many
the present
issues
a
envision
technician
highly
maintenance
the
intelligence
artificial
a
(perhaps
it
little
relatively
have
device.
design
who
people
assistant
provokes an enormous disparity
equipment
who
technicians
any
art
in
remain
versatile
the
trouble
An
important
display
graphics
a
about
important
for assembly
subclass
of the visual
that
postulate
visual
memory,
with
comfortable
thing,
ie,
thinking,
transformations.
presentation
together),
be an
graphics
the
in
it
For example,
a
as
group,
is
but one
factors
the
their
pictorial
than accountants
an
engineer
built
which
to each
prefer
might
sculptor
whereas a
at
of
representations
certain
model he can look
be
that
assert
quantify
of a builing,
blueprints
must
fit
involved.
people can simply be accustomed or are more
Additionally,
3-D
spatial
to
to
pressed
hard
and so
3-D information
information
as
are "more visual"
architects
of
manner
disassembly will
and
dramatically
plausible
quite
seems
pieces
vary
and geometrical
all
sequences,
people
such
abilities
(how
be a
will
present.
upon to
be called
system will
We
assembly
orders
strategic
showing
when conveying
7
mechanical
system
animated
parts,
particular
In
a
such
of
capable
text,
blueprints,
forth.
of
component
and perhaps
can accomodate
same
to examine
would
even touch.
"personalize"
the
like
5 -
a
Systems
their
needs and preferences.
individual's
-
or
the
is
thesis
This
visualization:
on
a
computer
techniques
have
manner allowing
used a
of
aspect of
with a specialized
concerned
the subproblem of representing
graphics
been
display.
Several
for expansion
as new ideas arise.
ones which will be used in the
video,
different
implemented for comparison,
style of computer graphics we believe is
scan digital
3-D solids
described
-
in
6 -
future,
in a
We have
exemplary
namely raster
the next section.
Scan Computer Displays
1.2
Raster
The
type of display used in
as "raster
scan",
to
understand
the distinction
and two earlier,
between
In
beginning
the
which could draw vectors
a
comprising
at
be repeated,
scheme
had
to
be
had
randomly
detailed,
flicker
it
more
disadvantages.
requiring
it.
to drive
causing the
As a
picture
take longer to go
frame
list,
repetition
(storage
noticeable
-
7 -
rate
was
until the
process would
avoid
to
positionable,
would
the vectors
all
as the display
enough
systems
between any two
Then the entire
serious
several
was interchangeable
another was drawn,
fast
rates
the early
around
of
table
known
exhasted.
complex electronics
list,
A
picture,
was
list
display
computer
vector
lines)
(straight
and one vector after
kept,
important
Vector graphics meant
screen.
the
on
points
graphics"
graphics".
"vector
with
is
video.
(of computer graphics),
phrase "computer
the
60's,
refered
new technology
this
"parent" technologies,
graphics and standard commercial
often
It
video".
or "computer
to
is
project
this
thru
to
tubes
flicker.
This
The CRT beam
and
costly
became more
the display
drop,
avoid
making
this
were
displays
was the
people,
the worst
Finally,
green.
oscilloscope
to
inability
sin of all
areas
display
monotonous
a
color 7
one
to
limited
Most
limitations).
other
have
but
problem
particular
to some
textures, and
7
photographic images.
In
it they would surely be extinct by now.
without
grace;
time dynamic effects,
Real
had one saving
displays
vector
however,
fairness
changing the positions of
ie
is a
without redrawing the entire display,
lines
operation
with vector graphics.
appropiate
part
In
picture.
the
with which
of the complexity of the
independent
scan systems the
raster
modifies
The ease
list.
of the display
can be done is
this
One simply
trival
exact opposite
is
the
case.
previously
screen
its
in
mentioned
disadvantages.
horizontal
sweeps,
deflection
to
scans.
frame,
scan is
stroboscopic
-
of
The beam scans
the
the
8 -
This pattern is
simplfying the
repeated 30 times a
complexity,
of picture
(although
it
frame
The
eletronics.
second regardless
flicker
from
same
the
many
going from top to bottom,
as
modulated
intensity
always
overcomes
technology
video
Commercial
effects
thus eliminating
can be seen on
objects)
moving
rapidly
commercial
However,
analog domain,
the
in
entirely
operates
video
color,
full
realistic,
can be shown.
images
photographic
Therefore
.
that is,
picture
information is carried by signals of continously
varying
amplitude.
generated digital video,
Computer
computer memory
the
number
in
buffer)
corresponding
each
to
modified
frame
specifying what
color
image can be
generated
or
any manner.
in
scan
raster
system
Model
an Interdata
around
with
the video
buffer,
a
called
by mathematically operating on
should be displayed. Thus,
frame
There is an n-bit
(sometimes
pixel
picture
resolvable
screen.
on the
pixel,
or
element,
offers
by constrast,
over every
control
explict
complete,
The
to
make or modify images.
arbitrarily
the
difficult
very
it
makes
This
dynamic
subroutines
modified
and
capabilities,
commercially
for
a
fast,
85,
based
is
thesis
this
minicomputer
16 bit
control store which permits microcoding of
critical
Architecture
used
augmented
available
of
which
to
are
equipment.
-
9 -
speed.
in
extensively
Group
Machine
some
improved
for
give
The 85 was
house
it
by
its
the
video
as yet unmatched in
Its
frame buffer
is
206k bytes large,
or
sixteen
translation
bits
and can run at one,
pixel.
per
and zooming on an
-
10
It
imarge in
-
two,
four, eight,
can
also
real
time.
perform
CHAPTER TWO
Techniques
3-D Display
2.1
Introduction
of
One division
3-D
1.2,
namely,
vector
vs.
limited
to
vector
3-D
scan.
raster
machines
at
machines
difference
are
is
irrelevant,
of section
that
Vector machines
raster
while
are
scan
of algorithms.
Of course,
than
raster scan
efficient
more
lines,
displaying
is
algorithms,
can use both classes
machines
vector
techniques
display
but
for our purposes this
so
we
use
scan
raster
throughout.
Several
different
schemes are described
in
this
chapter,
implemented. They are:
and four of them are currently
1)
Simple wire frame
2)
Hidden lines
3)
Hidden surfaces, no shading, with transparency
effects
-
11
-
4)
Hidden
surfaces,
-
shading,
12 -
and no transparency.
Vector 3-D
2.2
A
wire
frame
projecting
of
each
the
small.
of
edge of the
and
their
3-D
a
3-D
solid
solid
is
created
by
onto the 2-D plane
Wire frame
viewing screen.
implement
displays
computational burden
are easy to
is
relatively
Also, an object's internal decription is merely a
of its
list
display
require
edges,
unlike
hidden
"topological"
Generating
surface algorithms which
knowledge
about
an
object.
this additional information can prove
to be a
substantial burden.
The
main
catch
with
unacceptable
generally
simplest objects.
One,
as
that
of
angle.
That is,
it
is
difficult
(faces)
every
edge
the
in
that
they
anything
but
reference
are
outlined
an x-ray
to interpret
these
-
13 -
the
vector
instead of
More serious
the solid,
to
still
is
the
from any viewing
lines that should be obscured,
remain visible,
are
two disadvantages.
in
displayed.
display
is
viewing
earlier
areas
explicitly
"hidden",
for
frames
There are basically
mentioned
is
displays,
being
wire
view in
pictures,
a
sense.
and
or
Thus
they can
sometimes
equally
valid
be
enough to permit
ambiguous
perspective
orientations
-
14 -
two different,
of the
solid.
2.2.1
An
Z Intensity Depth Cuein
easily
somewhat
drawn
implemented
limited value,
vectors
vector in z,
drawbacks
effectiveness
Second,
z values,
with
to
aid
depth
modulation
is
respect
to
perception
of the
depth.
The
intensity
7
of
of
further the
the darker the intensity assigned to it. The
to
the
method
are
drops
with
increasing
twofold.
picture
First,
the
complexity.
if the vectors all fall within a narrow range of
the change
in
brightness
of use.
-
15 -
may be
too small to be
2.2.2
Hidden Line Removal
with
Dissatisfaction
eliminate
should be
obscured by
removal
line
a
surface
routine
scope 7
on
lines"
substantially
surface"
Hidden
"visual
in the
easier
algorithm.
can
routine
as a
implemented
one has no
a
raster
to come by,
We shall
used
be
special
case.
for this
thesis.
-
se
typically
are
expensive computationally.
implement and quite
vector
per
packages
line
hidden
to
"hidden
edges which
of an object.
However,
On
These
orientation.
the perspective
causes an enormous increase
intelligibility"
complex
of
portions
any edges or
routines
the
to
led
algorithms.
line"
of so called "hidden
development
interpretation
displays
frame
wire
simple
of
problems
and
clutter
the
This
16 -
see
to
is
choice.
scan
The analog to
machine,
"hidden
is known as a
shortly
simulate
that
a
how hidden
and
a hidden
hidden
lines
line
were
2.3
Raster Scan 3-D
In this case, the areas are the
ability to display areas.
viewing angle are
Advanced
systems
detailed
and
from a
given
This produces a
image,
in full color.
interpretable
of
images,
as
can
sort
this
realistic
such
fields
many
seen
in fact not displayed.
readily
convincing7
should not be
that
faces
of
portions
or
Faces,
solid we wish to be rendered.
the
of
faces
scan's
raster
the
exploit
algorithms
surface
Hidden
produce extremely
and are
finding uses
animation
scientific
in
time
and real
flight simulators.
one immediate advantage of the hidden surface approach is
the
ability
to
relative
solids
that
are
easily
the
color
point.
In
opaque
an
method
helpful
top layer of solids transparent
to render a
for
bottom layer.
seeing
relations
are normally blocked.
created
by using a
equation
displayed
form we
between adjacent
Transparency effects
weighted average between
and the
of the top layer
Transparency is a
bottom layer
have
color=alpha*bottom+ (1-alpha) *top.
-
17
-
at
each
Alpha
1,
is
the percentage
where
a value
of
a value
of transparency
of 1 makes
0 makes the
top
-
running
the top layer
layer
18 -
opaque.
invisible,
from 0 to
and
2.3.1
If
Hidden Surfaces without Light Source Shading
display
we
color,
object
with
we may have trouble
to
crucial
problem
like
an
is
a
to enhance
hidden
lines
line
a 3-D effect.
the edges
This
number of
colors
faces
faces,
One way
of the object.
the same
which is
around
the
surfaces,
is an appropiate
are available.
-
19 -
faces
to black,
alluded to
this
This looks
display superimposed on the
from hidden
2.2.2).
its
distinguishing
(by setting
display
surface
hidden
achieving
all
in
hidden
we get
section
technique when a limited
2.3.2
Surfaces with
Hidden
Instead of using the
we
a
add
may
light
source,
angle
its
If
have
the
a
parallel
distance
finite
face
to
compute.
with the
is
be
each
since all
other.
from
an object
non-uniform,
and
a
the
causes
thus
source
light
are
at a
shading of a
to
shading is that
it requires many more distinct colors than not
20 -
it.
more difficult
The only disadvantage of using
-
the
face will
rays hitting
light
Putting
to
striking
each
then
infinity?
at
rays
light
solid,
simulating a
face according
each
shading
and
uniform shade,
to
depth cue by
very effective
source
Shading
same color for each face of a
normal makes
light
Source
Light
shading.
2.3.3
A
Hidden Surfaces with Shading and Shadows
refinement
section
blocking
is
to
a
more complex
visualization
of
light
the
show
shading
technique
This method
source.
than simple shading.
is
to
difficult
-
by parts
cast
shadows
Its
assess at
21 -
of the
is
value
this
previous
of an
object
substantially
in
aiding
time.
3-d
CHAPTER THREE
SOMA Puzzle Animation
3.1
The
The
SOMA
SOMA Puzzle
puzzle
in
achieve
a
column
Games
Mathematical
which make
it an
of 3-D visualization
study
the
for
medium
attractive
to hold his
went on to
the Appendix,
in
detailed
during a
For our purposes it has various
Scientific American.
properties,
Hein,
which failed
Gardner's
Martin
via
following
by Piet
puzzle
intriging
The
attention.
invented
mechanics
quantum
on
lecture
was
problems.
blocks,
solid
or
unit
four
each constructed
look quite
assembled
into
most
surprising
they
can
be
put
count
symetries
ways).
On the
the hundred
to
together
and
other hand,
-
Although the pieces
and
forty
form a
some figures
22 -
they can be
pleasing shapes.
there
rotations
three
joining together
and unwieldy,
irregular
many simple and
is
by
faces.
cubes on their
themselves
pieces,
of seven different
the puzzle consists
Briefly,
ways
different
3x3x3 cube
are
Perhaps
(if
you
over a million
may be
built
in
only
one
way,
or phrased differently,
figure" may have only one
-
a
given "target
"solution configuration".
23 -
Animation Techniques
3.2
So
far,
static
arbitrary
display
will
programs has been developed
of
a -collection
These
in
enhanced
are
styles.
animated
sequences of the SOMA blocks
animation
known computer
The idea
frame,
technique,
produce
dynamic motion.
in
a well
of
animation.
key frame
frame, an end
and the number of intermediate frames in which the
to end takes place.
start
from
interpolates
between
intermediate
ones.
key
two
the
frames to
is
so
need only be done on
quite
frames.
pieces are
of the SOMA
the shape
the
create
change between key
our case however,
interpolation
The computer
key framing
general,
In
since shapes can
difficult,
In
fixed
position,
spatial
and color.
orientation,
program
was
written
of
the
can
which
corresponding
configurations
output
order to
specify a start
in key frame is to
transition
A
several
simple application
by a
accomplished
is
This
in
configurations
different
which
to
finding
solution
-
24 -
find
all
solution
The
the target
figure.
program is
each block's
spatial
and
position
orientation in the target
figure.
This description can then be used as input to the display
Chapter 2.
in
programs described
sequence of scattered pieces comming
Therefore, showing a
parameters
the
giving
requires
only
together
and the
configuration
initial
disjoint
figure.
Pieces can move simultaneously,
a time.
at
one
move
interpolation
simple
this
One disadvantage
completed
in
for the
target
subgroups, or
(but fun to watch)
scheme
of
is that since blocks
in a straight line between start and end frame, they
pass
each
thru
ignoring
other,
world physical
real
constraints.
capable
disk
then
video
does
in
real
standard
rates,
For images of moderate
not posses the computatial
time,
ie
frame of
from the 85.
available
played back at
tape.
single
recording a
of
time as they become
is
are made by using a video
time sequences
real
Currently
30 times a
-
The video disk
recorded onto
complexity,
power to generate
second.
25 -
and
a
video at
the
85
frames
Appe ndi ix
Idiosyncratic
in
The
Systems:
of
adoption
a
blocks-world
how
puzzles,
aid
to
The
study
AI
paradigm
aim is
but insights
can
are
understanding
explication
paradigm
parameters
problems
central
block
re of a 3-D mechanical
machine
rich
yet holding certain
focus on
of
into
a
solve
to understand better how to
functions
not that
sake of teaching
and to
figures
block
their
puzzles
assembly,
make
in
blocks world,
Block
in
classic
feasible
for the
not
paradigm,
but because we wish
people
world.
is
A
vision".**
"computer
for
world
"blocks"
study we are proposing is the advised adoption of
for the
people
Personalized Perspectives
the Explication of Mechanical Assemblies
paradigms
a
proposal,
3.3 of the ONR
Section
of a
via machine.
for
mechanical
constant
of presentation
so that
and
of aiding understanding.
**Cf.
Winston,
P.H.
(Ed)
The psychology of computer
1975;
Kuipers, B.J. "A
McGraw-Hill,
vision.
New York:
In Bobrow, D.G. & Collins, A. (Eds.),
frame for frames".
New York:
Academic
understanding.
and
Representation
Press, 1975
-
26 -
Consider
is
to
the
form
component
a
wooden
cube
pieces.
recommend
the
classic
it.
from
blocks puzzle
about
the aim
ten irregularly
formed
the puzzle has much to
As a paradigm,
The aim of the activity
assemblages
where
of the puzzle.
is
well-
The process
defined:
of assembly
involves selection at every sub-stage of assembly.
is
component
a
puzzle:certain
of
of
insertion
the
to
that
is
it
arise
from the
of
the
a
part
sub-assemblies
dependency,
or
in that
jutting part that
erroneously
puzzle-solver
by
often possible to
only
later,
wood
there
is
puzzle game,
of
a cube.
27
not be
cueing in
that
doesn't
considerations
is
In
usually
only
of assembly
constrast,
invented by Piet
-
may
thus far.
one pattern
SOMA,
-
a piece
of global
there
only
may or
such direct
place
out
puzzle
the end criterion
the cube
the
impossible because part
edge
"look" of the assembly
classic
solution:
meets
an
into
it.
signaled
With
has
built
only into
of a piece can be
placement
belong
"fit"
There is structural
assemblage
prevents
The
dependency
pieces will
formed earlier.
the
serial
There
one
that
consider
Hein,
and
marketed
in
America
by Parker
cube to be assembled
7
irregular
is
a
pieces
unit-cube.
Again,
Brothers Games,
3x3x3-unit
which
there is
are
one
if
one
each
solution:
other
using
the SOMA
a
the
cube or of its
cube,
ways
that
can arise
up out of
of
cube.
the
But now
been calculated
to
form the cube,
are reflections
of
from each other by whole
several
parts.
solution,
to
bonus
is
from
the
varied
target/figures,
ranging
difficult,
that
general,
comprise a
at
the
end
systematically
problem
set
(cube)
SOMA
goal
of
well
as
the
as
of
with mode and
of this
block
of an
admits
The interaction
the heart
proposal.
pieces
is
assembly
there
that
can be
are
many
from the very simple to the very
can be constructed
then,
can be one that
or of many.
task completion
of explication
further
vary aspects
The assembly task
means
additionally,
In
has
one can systematically
task.
variable
A
that
unique
strategy
solutions
a
The
both the simple classic wooden cube puzzle and
assembly
of
all
or
of
It
exactly 1,105,920
considers
rotations
By
are
there
made
combinations
there are many paths to that end.
that
cube,
Inc.
from the
pieces.
the wood blocks and the SOMA blocks
where there
-
28
-
can be clearly
defined
ends,
either
and
a
routes.
Surely,
solution
should
the
But
experimenter
with
an
namely,
"repair"
of
task,
a "damaged"
presentational
brought
bear:
strategies,
to
examples
and
assembly,
factors
re-presentation
of
at
bear
solution,
defined
both for
the
i.e.,
"time
the total
to
target
sub-assembly.
assembly
(or,
possibly,
variants
of explication
ranging
inputs,
perhaps
end,
a
measure;
directions;
in
can be
from hinting
diagramatics;
bearing
the
visual
"Hints";
intersection
of
strategies.
affecting
the presentation
"real-world"
evaluating
counterexamples;
and verbal
from
for
and modes
explicit
sequences,
Apart
criteria
cube
verbal
animation
graphical
afford
block configuration),
strategies
to
sets
any defineable
the basic suject
ends to a
the methodology of
a clearly
measure,
for
many
or many
the block
success/failure
as well as
Given
of
temper
tangible
completion" criterion
figure,
and
all along,
performance:
overall
availability
modify
explication.
subject
unique route to any end,
explication
of an on going
of the problem
the problem as
study.
mechanical
The
problems
-
29
-
it
initially,
and
undergoes
attempts
analogue
is
that
here
with
differing
or
radically
a
of
be
may
stage b.
complexity than at
stage was
We are all
familiar with the
jigsaw puzzle of "the
while recalling how
so easy (Do
the
edges first!),
the
early
how
slow-going were the middle stages.
of
the
how
problem,
profound
effect
Schwartz,
S.
solving:
upon
H.
prospects
well-evolved
is
half
Experimental Psychology, 1971, 91
This proposal has alluded to
the
idle
psychology
at
can
presentation
solution.
a
A
proper
and problem
Journal
of
347-350).
in
perspectives":
This is no
his recent doctoral dissertation in
seemingly
John Banjafield
showed
small difference in problem
dramatically
affect
prospects
simple "block puzzle" was used,
pyramids
identical
(2),
(Cf.
solution,
solved",
"personal
Brandeis University,
how
dramtically
the
In
metaphor.
can have a
of item assembly.
aspects
visualization
for
and
total "look"
representation
of
"Modes
The
re-presented,
is
it
visual
order
to solve itself",
beginning
puzzle
of
different
doing a
end of
toward the
effect,
stage a of assembly
at
of the sub-assembly
gestalt)
("look"
configuration
total
the
For example,
progresses".
as assembly
"indicated
may be
explication
of
approaches
of wood,
for
two small
which when put together
in
larger pyramid of similar form.
way formed a
-
30 -
The
2)
table-top;
where the blocks
1)
of two manners:
holder.
small
by
a
position
of
the blocks was the
above
both
same in
the
the relative
Otherwise7
tabletop
on a
presented
were
supported
were
they
where
either
in
subjects
presented to different
blocks were
conditions.
The task was to examine the blocks without touching them,
and
not
blocks.)
the
for
superiority
or
look
of
seemed to prevent subjects from performing the
firmness,
mental
necessary
of
part
involving
of
one
manipulation
and
rotation
blocks
the
tabletop in order to
the
through
of the
"palpability"
its
above-the-tabletop,
so that the only
"look"
striking
a
showed
data
the
they could
(i.e.,
assembly,
was
difference
experimental
The
to
prior
"handled"
be
them
put
to
directly
pyramid.
larger
form the
to
together
and
up
them
pick
to
then
which
extending down
form the proper figure
for solution. Whatever the exact nature of the underlying
phenomena7
with
the
functional
was dramtic
difference
much greater success for these
mental
operation
that
subjects who had the
was compatible
mode that
presentational
was
a
indeed,
sufficient
with the sort
condition
of
for
solution.
Problem
variants
for a SOMA blocks paradigm can
-
31 -
include
the
not.
The conjoint
level
of
parts
Block
portrayed blocks.
could be color-coded
or
its
examined re
be
can
transparency
of
color coding and varying
of
variation
pieces
of the component
the transparency
in
variations
such as
operations
user-controlled
and
user-initiated
on
effects
performance.**
view
of
aspect
in
differences
with block puzzle
"real-world"
actual
3-D mechanical
parallel
conceptualization
interest.
For example,
whether
subjects
the
second
of
part
of the
first
**Reed,
of visual
can
has
Reed**
as well as with
the issue
of
is
more
vs.
of serial
than
passing
studied the problem of
judge whether
successfully
presented patterns
two sequentially
etc.),
comprehension.
paradigmatics,
assembleges,
critical
parallel;
(axonometric;
projection
can be powerful aids to
Lastly,
but possible
as well as subtle
the
to control
the observer
of
ability
the
rotation,
color,
control of tranparency,
observer
with
Together
dimension.
presentational
this
in
personalization
providing
literally
varied,
be
can
Perspective
or not
is
pattern.
descriptions
S.K. Structural
images. Memory & Cognition,
-
32
-
and the limitations
329-336
1974 2(2),
a
His
results
that
suggested
subjects
subsequently find it
structural descriptions, and
recognize
a
part
description.
of the pattern
Further,
visual
and
verbal
detail
when
not
suggested
and that
codes,
visual
of
mixture
both
"procedures",
any
of
and,
sub-assembly
with
mental
different
visual images.
model
verbalized
of itself,
of
it,
to-be-completed
task
has thus
he
problem
Exploration
of the SOMA
to
in
may
open
far
done,
may be a
descriptions
blocks world
that
way
amalgamation might be,
explicate
compatible
-
33 -
the
the
model for
space,
procedural
facility
in
The assembler's
compound of
what this
how
what
in
is")
graphics
comprehension
of
model
he
"where
our
intimate
so far
accomplished
the assembler what he has done thus far.
radically
that an
that the direct visual
2)
course of an overall task may not,
internal
lack
and that explication protocols need to take
both aspects into account;
and
1)
and
"pictures"
visual
of
For our
components may be an
3-D visualizable
involving
a
an assebmly task
during
orientation
mental
operator's
(i.e.,
images
verbal detail.
by
supported
that
combination
these findings suggest two things:
purposes
aspect
results
comprised of a
is
description
structural
hard to
does not match the
that
the
as
code patterns
balance
modes and
for
how to
of
media.
the
(The
author
Architecture
of
this
section
Machine Group.)
-
34 -
is
Dr.
Richard
Bolt,
REFERENCES
"An Algorithm
Bouknight, W.J., Kelley, K.C.
Presentations
Graphics
Computer
Half-Tone
1970,
SJCC
Sources."
Light
Movable
and
Montvale, N.J.,l.
Producing
for
with Shadows
AFIPS Press,
"An Image Processing Approach to Computer
Entwisle,
J.
Graphics."
IEEE
on Computer Graphics,
Conference
July,
1974.
Negroponte,
Graphics."
Negroponte,
N.P.
Computers
N.P.,
Effects
Transparency
Report to U.S. Army
29-76-C-0037.
"Raster
Scan Approaches to Computer
and Graphics, 2,
Bolt,
R.A.,
1977,
179-193.
and Tom,
V.
"Color
Opaque Colors."
of
From Mosaics
number DAAG
Contract
Research Office,
W.M., and Sproll, R.F.
Newman,
Computer Graphics. McGraw Hill,
Principles
Inc. 1973.
of Interactive
Sproll, R.F, and Schumacker, R.A., "A
I.E.,
Sutherland,
Algorithms."
Surface
Hidden
Ten
of
Characterization
number N
contract
the Office of Naval Research,
Report to
00014-72-C-0346.
-
35 -
Acknowledgements
Thanks to:
The Office of Naval Research
for
Bill
Donelson for helping me
use his
hidden surface routines
The Architecture
Machine
sponsoring this
7
for being,
Nicholas Negroponte, my thesis
for making it all possible,
advisor,
and Bonnie Biafore, who got me into to
all this in the first place,
and helped me get out as well...
-
36
-
work 7