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U.S. Patent #6,515,662
Following is the complete patent document copied from the U.S. Patent and Trademark website. Selected images of figures are available to the left.
| United States Patent |
6,515,662
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Garland
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February 4, 2003
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Computer apparatus for providing stereoscopic views from monographic images
and method
Abstract
A computer apparatus modifies monographic datamap images into monographic
display images in stereoscopic relationship for presentation to a
bi-ocular observer such as a person. A stereoscopic (SS) spacing is
defined between the left and right virtual viewing points (VVPs) of the
observer relative to an initial VVP. A display vertex generator modifies
each datamap vertex to generate a corresponding display vertex in the left
and right display rasters. The magnitude of the modification is based on
the left and right VVPs and on the range coordinate of that datamap
vertex. An over-ride feature checks the SS spacing between the left and
right display images, and replaces them with a default SS spacing whenever
the checked spacing exceeds a predetermined over-ride spacing. A
stereoscopic viewing device is responsive to the channels for presenting
the display rasters to the left and right eyes of the observer.
| Inventors:
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Garland; Harry B. (Mountain View, CA)
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| Assignee:
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Canon Kabushiki Kaisha (Tokyo, JP)
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| Appl. No.:
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120024 |
| Filed:
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July 16, 1998 |
| Current U.S. Class: |
345/427 |
| Intern'l Class: |
G06T 015/20 |
| Field of Search: |
345/427
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References Cited
U.S. Patent Documents
| 4870600 | Sep., 1989 | Hiraoka | 364/522.
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| 4962422 | Oct., 1990 | Ohtomo et al. | 358/88.
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| 5379369 | Jan., 1995 | Komma et al. | 395/119.
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| 5519485 | May., 1996 | Ohtani et al. | 356/2.
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| 5594843 | Jan., 1997 | O'Neill | 395/127.
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| 5917539 | Jun., 1999 | Sorensen et al. | 348/56.
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| 5929861 | Jul., 1999 | Small | 345/427.
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| 5953013 | Sep., 1999 | Shimizu | 345/419.
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| 5953014 | Sep., 1999 | Wood | 345/422.
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| 5973831 | Oct., 1999 | Kleinberger et al. | 359/465.
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| 6023263 | Feb., 2000 | Wood | 345/139.
|
| 6031564 | Feb., 2000 | Ma et al. | 348/43.
|
| 6055012 | Apr., 2000 | Haskell et al. | 348/48.
|
Other References
"Computer Graphics: Principles and Paractice" by James D. Foley et al.,
second edition, published by Addison-Wesley 1990, ISBN 0-201-12110-7 at
pp. 915-917.
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Primary Examiner: Zimmerman; Mark
Assistant Examiner: Santiago; Enrique L
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper & Scinto
Claims
What is claimed is:
1. Computer apparatus for modifying monographic datamap images into
monographic display images in stereoscopic (SS) relationship for
presentation to a bi-ocular observer having a first eye and a second eye,
comprising:
buffer memory means for storing a datamap raster containing a monographic
datamap image of polygons defined by polygon vertices from a polygon based
graphics datamap, in which each vertex has a position in a three
dimensional coordinate system defined by a traverse coordinate and an
elevation coordinate and a range coordinate;
a first and a second stereoscopic channel for processing the datamap raster
stored in the buffer memory means forming a first and a second display
raster containing a first and a second monographic display image at a
first and a second virtual viewing point (VVP), for presentation to the
first and the second eye of the observer;
stereoscopic (SS) spacing means for defining a SS spacing between the first
and second VVPs;
initial virtual viewing point means defining the position of an initial
virtual viewing point (initial VVP) for the datamap raster;
display virtual viewing point means for providing the first and second VVPs
in SS relationship based on the position of the initial VVP and on the SS
spacing;
display vertex generator in the first and the second channel, for modifying
each datamap vertex in the datamap raster to generate a corresponding
display vertex in the first and the second display raster based on the
first and the second VVP and on the range coordinate of that datamap
vertex;
stereoscopic viewing device responsive to the first channel for presenting
the first display raster containing the first display image to the first
eye of the observer, and responsive to the second channel for presenting
the second display raster containing the second display image to the
second eye of the observer; and
a stereoscopic spacing over-ride means for checking the SS spacing between
the first and second display images in SS relationship by comparing the
first VVP position with the second VVP position, and for replacing the
checked SS spacing with a default SS spacing whenever the checked spacing
exceeds a predetermined spacing.
2. The computer apparatus of claim 1, wherein the initial VVP and the SS
spacing are instructions stored in the buffer memory means, and the
display virtual viewing point means is a display virtual viewing point
generator responsive to these instructions.
3. The computer apparatus of claim 2, wherein:
the first VVP in the first channel is the initial VVP; and the display
virtual viewing point generator is in the second channel for modifying the
initial VVP of the datamap raster based on the full SS spacing to provide
the second VVP in SS relationship with the initial VVP.
4. The computer apparatus of claim 2, wherein the display virtual viewing
point generator is in both the first and second channel for modifying the
initial VVP of the datamap raster based on one half of the SS spacing to
provide the first VVP and the second VVP in SS relationship with the
initial VVP.
5. The computer apparatus of claim 1, wherein the SS spacing means is a
graphics instruction stored in the buffer memory means defining the SS
spacing.
6. The computer apparatus of claim 1, wherein the SS spacing means is an
observer entered instruction defining the SS spacing.
7. The computer apparatus of claim 6, wherein the SS spacing means further
comprises a graphics instruction stored in the buffer memory means
defining an initial SS spacing which may be changed by the observer
entered instruction.
8. The computer apparatus of claim 1, wherein the datamap image contained
in the datamap raster forming the first display raster is identical to the
datamap image contained in the datamap raster forming the second display
raster.
9. The computer apparatus of claim 1, wherein the buffer memory means
provides a sequence of datamap rasters, and further comprising;
raster assignor for assigning the datamap rasters from the buffer memory
means to the first channel forming a first sequence of display rasters for
presentation to the observer's first eye, and to the second channel
forming a second sequence of display rasters for presentation to the
observer's second eye.
10. The computer apparatus of claim 9, wherein the display vertex generator
further comprises;
a first display vertex generator in the first channel for generating
display vertices in the first sequence of display rasters; and
a second display vertex generator in the second channel for simultaneously
generating display vertices in the second sequence of display rasters.
11. The computer apparatus of claim 10, wherein the raster assignor is a
raster alternator for assigning every other datamap raster to the first
channel, and for assigning the alternate every other datamap raster to the
second channel.
12. The computer apparatus of claim 1, wherein the three dimensional
coordinate system is an XYZ Cartesian coordinate system having an X
traverse coordinate and a Y elevation coordinate and a Z range coordinate.
13. The computer apparatus of claim 1, wherein the three dimensional
coordinate system is a polar coordinate system having an azimuth angle
traverse coordinate and a pitch angle elevation coordinate and a radius
range coordinate.
14. The computer apparatus of claim 1, wherein the first VVP and the second
VVP are spaced along a stereoscopic display axis parallel with the
traverse coordinate, and the display virtual viewing point means provides
the first and second VVPs by shifting the value of the traverse
coordinate.
15. The computer apparatus of claim 1, wherein the stereoscopic viewing
device comprises:
a monitor for alternately displaying the first display image and the second
display image;
a first shuttered LCD viewing window for alternately passing the first
display image to the first eye of the observer and blocking the second
display image; and
a second shuttered LCD viewing window for alternately passing the second
display image to the second eye of the observer and blocking the first
display image.
16. The computer apparatus of claim 15, wherein the shuttered LCD viewing
windows have a clear orientation for passing the display images and have
an opaque orientation for blocking the display images.
17. The computer apparatus of claim 15, wherein the shuttered viewing
windows are portable goggles worn by the observer.
18. The computer apparatus of claim 15, wherein the shuttered viewing
windows are stationary viewing ports.
19. The computer apparatus of claim 1, wherein the stereoscopic viewing
device comprises:
a first head mounted monitor for displaying the first display image to the
first eye of the observer visually isolated from the second display image;
and
a second head mounted monitor for displaying the second display image to
the second eye of the observer visually isolated from the first display
image.
20. The computer apparatus of claim 19, wherein
the first stereoscopic channel is a left front stereoscopic channel for
presenting a left front monographic display image at the first virtual
viewing point (first VVP) to the left eye of the observer; and
the second stereoscopic channel is a right front stereoscopic channel for
presenting a right front monographic display image at the second virtual
viewing point (second VVP) to the right eye of the observer.
21. The computer apparatus of claim 19, further comprising:
a left peripheral monographic channel for presenting a left peripheral
monographic display image to the left eye of the observer forming a
monographic wrap-around image with the left front display image; and
a right peripheral monographic channel for presenting a right peripheral
monographic display image to the right eye of the observer forming a
monographic wrap-around image with the right front display image.
22. The computer apparatus of claim 21, wherein the stereoscopic viewing
device comprises:
a left front head mounted monitor for displaying the left front display
image to the front of the first eye of the observer visually isolated from
the right front display image;
a right front head mounted monitor for displaying the right front display
image to the front of the second eye of the observer visually isolated
from the left front display image;
a left peripheral head mounted monitor for displaying the left peripheral
display image to the left periphery of the first eye of the observer
visually merged with the left front display image to provide a wrap-around
monographic left image; and
a right peripheral head mounted monitor for displaying the right peripheral
display image to the right periphery of the second eye of the observer
visually merged with the right front display image to provide a
wrap-around monographic right image.
23. A computer implemented method of modifying a single monographic datamap
image into two monographic display images in stereoscopic (SS)
relationship for presentation to a binocular observer having a left eye
and a right eye, comprising the steps of:
providing a datamap raster containing a datamap image of polygons defined
by polygon vertices from a polygon based graphics datamap, in which each
vertex has a position in a three dimensional coordinate system defined by
a traverse coordinate and an elevation coordinate and a range coordinate;
providing a left and a right image channel for processing the datamap
raster forming a left and a right display raster containing a left and a
right monographic image at a left and a right virtual viewing point (VVP)
for presentation to the left and the right eye of the observer;
defining a stereoscopic (SS) spacing between the left and right VVPs;
defining the position of an initial virtual viewing point (initial VVP) for
the datamap raster;
determining the left and right VVPs in SS relationship based on the initial
VVP and on the SS spacing;
modifying each datamap vertex in the datamap raster to generate a
corresponding display vertex in the left and the right display raster
based on the left and the right VVP and on the range coordinate of that
datamap vertex;
checking the spacing between the left and the right display raster in SS
relationship by comparing the left VVP position with the right VVP
position;
replacing the checked spacing with a default SS spacing whenever the
checked spacing exceeds a predetermined over-ride spacing;
presenting the checked left display raster containing the left monographic
image to the left eye of the observer; and
presenting the checked right display raster containing the right
monographic image to the right eye of the observer in SS relationship with
the left monographic image.
24. The computer implemented method of claim 23, wherein the left
monographic image has a left presentation mode and the right monographic
image has a right presentation mode which is distinguishable from the left
presentation mode.
25. The computer implemented method of claim 24, wherein the step of
presenting the display rasters to the observer further comprises the step
of:
distinguishing the left presentation mode from the right presentation mode
through a stereoscopic viewing device.
26. The computer implemented method of claim 25, wherein the step of
distinguishing the presentation modes further comprises the step of:
shuttering the stereoscopic viewing device for alternately passing the left
image in the left presentation mode to the left eye of the observer while
blocking the right image in the right presentation mode, and then blocking
the left image in the left presentation mode while passing the right image
in the right presentation mode to the right eye of the observer while.
27. A computer readable medium containing a computer program that modifies
a single monographic datamap image into two monographic display images in
stereoscopic (SS) relationship for presentation to a binocular observer
having a left eye and a right eye, by directing the computer to execute
the steps of:
providing a datamap raster containing a datamap image of polygons defined
by polygon vertices from a polygon based graphics datamap, in which each
vertex has a position in a three dimensional coordinate system defined by
a traverse coordinate and an elevation coordinate and a range coordinate;
providing a left and a right image channel for processing the datamap
raster forming a left and a right display raster containing a left and a
right monographic image at a left and a right virtual viewing point (VVP)
for presentation to the left and the right eye of the observer;
defining a stereoscopic (SS) spacing between the left and right VVPs;
defining the position of an initial virtual viewing point (initial VVP) for
the datamap raster;
determining the left and right VVPs in SS relationship based on the initial
VVP and on the SS spacing;
modifying each datamap vertex in the datamap raster to generate a
corresponding display vertex in the left and the right display raster
based on the left and the right VVP and on the range coordinate of that
datamap vertex;
checking the spacing between the left and right display rasters in SS
relationship by comparing the left VVP position with the right VVP
position;
replacing the checked spacing with a default SS spacing whenever the
checked spacing exceeds a predetermined over-ride spacing;
presenting the checked left display raster containing the left monographic
image to the left eye of the observer; and
presenting the checked right display raster containing the right
monographic image to the right eye of the observer in SS relationship with
the left monographic image.
28. The computer readable medium of claim 27, wherein the step of defining
the SS spacing is executed within the source code of the computer program.
29. The computer readable medium of claim 28, wherein the step of defining
the left and right VVPs is executed within the source code of the computer
program by modifying a set VVP instruction.
30. The computer readable medium of claim 29, wherein the set VVP
instruction is modified between the initial VVP and either the left VVP or
the right VVP.
31. The computer readable medium of claim 29, wherein the set VVP
instruction is modified between the left VVP and the right VVP.
Description
TECHNICAL FIELD
This invention relates to providing stereoscopic views based on monographic
images from a three dimensional datamap.
BACKGROUND
Heretofore datamaps based on an XYZ coordinate system (3D) have been
employed to provide a sequence of monographic images of display objects
along X and Y display coordinates (2D). The Z or range coordinate provided
a depth dimension effect which supported 3D like features such as:
parallax shift between display objects at different depths;
occulting of distant background objects by closer foreground objects; and
keystone taper of objects faces toward a vanishing point.
However, these depth effects did not include direct visual range perception
between left and right monographic images in stereoscopic relationship.
SUMMARY
It is therefore an object of this invention to provide multiple monographic
images in stereoscopic relationship which support direct perception of
range.
It is another object of this invention to provide such stereoscopic
relationship with controlled stereoscopic spacing for enhancing the range
perception.
It is a further object of this invention to provide such stereoscopic
relationship by shuttering the monographic images presented to the
observer.
It is a further object of this invention to provide such stereoscopic
relationship through head mounted monitors which present the monographic
images to the observer.
It is a further object of this invention to provide such stereoscopic
relationship through head mounted monitors with front and peripheral
images in wrap-around relationship.
Briefly, these and other objects of the present invention are accomplished
by providing a computer apparatus for modifying monographic datamap images
into monographic display images in stereoscopic relationship for
presentation to a binocular observer. A buffer memory stores datamap
rasters containing monographic datamap images of polygons defined by
polygon vertices from a polygon based graphics datamap. Each vertex has a
position in a three dimensional coordinate system defined by a traverse
coordinate and an elevation coordinate and a range coordinate. A left
stereoscopic channel processes datamap rasters stored in the buffer memory
forming left display rasters containing left monographic display images at
a left virtual viewing point (left VVP), for presentation to the left eye
of the observer. A right stereoscopic channel processes datamap rasters
stored in the buffer memory forming right display rasters containing right
monographic display images at a right virtual viewing point (right VVP) in
stereoscopic relationship to the left display images, for presentation to
the right eye of the observer. Stereoscopic spacing mechanism defines a
stereoscopic spacing between the left and right VVPs. An initial virtual
viewing point mechanism defines the position of an initial virtual viewing
point (initial VVP) for the datamap raster. A display virtual viewing
point mechanism provides the left and right VVPs in stereoscopic
relationship based on the position of the initial VVP and on the
stereoscopic spacing. A display vertex generator in the left and right
channels, modifies each datamap vertex in the datamap raster to generate a
corresponding display vertex in the left and right display rasters based
on the left and right VVPs and on the range coordinate of that datamap
vertex. A stereoscopic viewing device is responsive to the left and right
channels for presenting the left and right display rasters containing the
left and right display images to the left and right eyes of the observer.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present computer apparatus and
method, and the operation of the stereoscopic viewing device, will become
apparent from the following detailed description and drawings (not drawn
to scale) in which:
FIG. 1A is a block diagram of a computer apparatus, a single display
monitor, and portable viewing goggles having shuttered viewing windows;
FIG. 1B shows a triangle representing a typical polygon display object
processed by the computer apparatus of FIG. 1A;
FIG. 1C shows a code format defining the triangle polygon display object of
FIG. 1B;
FIG. 2 shows a block diagram of a graphics processor unit, a single
monitor, and stationary viewing ports having shuttered viewing windows;
FIG. 3 shows a block diagram of a graphics processor unit, and multiple
head mounted monitors displaying front and peripheral views;
FIG. 4 shows the basic steps and sub-steps of the general method of
processing and presenting the stereoscopic views;
FIG. 5 is a source code flow chart showing the modification of monographic
object code into stereoscopic object code; and
FIGS. 6A and 6B show monographic source code instructions before and after
modification.
The first digit of each reference numeral in the above figures indicates
the figure in which that element is most prominently shown. The second
digit indicates related structural elements, and a final letter (when
used) indicates a sub-portion of an element.
REFERENCE NUMERALS IN DRAWINGS
The table below lists all of the reference numerals employed in the
figures, and identifies the element designated to by each numeral.
10 Computer Apparatus 10
10A Application Programming Interface 10A
10B Buffer Memory 10B
10C Central Processor Unit 10C
10E Geometry Engine 10E
10M Graphics Datamap 10M
10L First Stereoscopic Channel 10L
10R Second Stereoscopic Channel 10R
10T Triangle Polygon 10T
12 Graphics Processor Unit 12
12A Raster Assignor 12A
12C Graphics Controller 12C
12P Display VVP Generator 14D
14D Display Vertex Generator 14D
16D Stereoscopic Display Axis 16D
16I Initial Virtual Viewing Point 16I
16L First Virtual Viewing Point 16L
16R Second Virtual Viewing Point 16R
18G Shuttered Goggles 18G
18M Display Monitor 18M
18L First Viewing Window 18L
18R Second Viewing Window 18R
20L Left Channel 20L
20R Second Channel 20R
22 Graphics Processor Unit 22
22A Raster Alternator 22A
22C Graphics Controller 22C
22L Left Virtual Viewing Point Generator 22L
22R Right Virtual Viewing Point Generator 22R
22S Stereoscopic Spacer 22S
24K Keyboard 24K
24L Display Vertex Generator 24L
24R Display Vertex Generator 24R
24S Over-ride Circuit 24S
26D Stereoscopic Display Axis 26D
26L Left Virtual Viewing Point 26L
26R Right Virtual Viewing Point 26R
28M Display Monitor 28M
28P Stationary Viewing Port 28P
28L Left Shuttered Viewing Window 28L
28R Right Shuttered Viewing Window 28R
30B Buffer Memory 30B
30L Left Front Channel 30L
30R Right Front Channel 30R
31L Left Peripheral Channel 31L
31R Right Peripheral Channel 31R
32 Graphics Processor Unit 32
32D Raster Doubler 32D
32L Left Front VVP Generator 32L
32R Right Front VVP Generator 32R
33L Left Peripheral VVP Generator 33L
33R Right Peripheral VVP Generator 33R
34L Left Front Vertex Generator 34L.
34R Right Front Vertex Generator 34R.
35L Left Peripheral Vertex Generator 35L.
35R Right Peripheral Vertex Generator 35R.
36L Left Virtual Viewing Point 36L
36R Right Virtual Viewing Point 36R
38L Left Front Monitor 38L
38R Right Front Monitor 38R
39L Left Peripheral Monitor 39L
39R Right Peripheral Monitor 39R
GENERAL EMBODIMENT (FIGS. 1A, 1B and 1C)
Computer apparatus 10 (shown in FIG. 1A) modifies monographic datamap
images from polygon based graphics datamap 10M into monographic display
images in stereoscopic (SS) relationship for presentation to a biocular
observer such as a person. Application programming interface (API) 10A
receives polygon data from polygon datamap 10M and a graphics program, and
interfaces between the codes in the graphics program and the circuits in
the computer apparatus. API 10A coordinates the operation of central
processor unit (CPU) 10C, geometry engine (GTE) 10E, and graphics
controller 12C within graphics processor unit (GPU) 12. Geometry engine
GTE 10E receives the polygon vertices from API 10A for calculating the
position of each datamap polygon vertex and the geometric relationships
between the datamap vertices. Buffer memory 10B stores a datamap raster
containing a monographic datamap image of polygon display objects such as
triangle 10T (see FIG. 1B) from polygon datamap 10M.
Each vertex of each polygon display object has a position in a datamap
three dimensional coordinate system defined by a generally traverse
coordinate (relative to the observer), and a generally elevational
coordinate (relative to the observer), and a range coordinate (relative to
the observer). The coordinate system may be any suitable system having
three dimensions such as an XYZ Cartesian coordinate system having an X
traverse coordinate and Y elevation coordinate and a Z range coordinate.
Alternatively, the coordinate system may be a polar coordinate system
having an azimuth angle traverse coordinate and a pitch angle elevation
coordinate and a radius range coordinate. The polygon datamap may be any
suitable data storage device of sufficient capacity such as a ROM. First
stereoscopic channel 10L within graphics processor unit 12 processes a
datamap raster stored in buffer memory 10B forming a first display raster
containing a first monographic display image at a first virtual viewing
point (first VVP) 16L, for presentation to the first eye of the observer.
Similarly, second stereoscopic channel 10R processes a datamap raster
forming a second display raster containing a second monographic display
image at a second virtual viewing point (second VVP) 16R for presentation
to the second eye of the observer. Raster assignor 12A assigns the datamap
rasters to the respective channels.
Stereoscopic Spacing
A suitable stereoscopic spacing mechanism defines a SS spacing (or angle)
between the first and second VVPs. The first and second display images are
monographic images, but are presented in left/right SS relationship
permitting the observer to mentally resolve the monographic images into a
composite stereoscopic view. The first VVP and the second VVP are spaced
along stereoscopic display axis 16D which is preferably parallel with the
traverse coordinate. The VVPs may be spaced along a horizontal
stereoscopic display axis, which is coincident with a horizontal
stereoscopic observer axis defined by a left observer viewing point (at
the observer's left eye) and a right observer viewing point (at the
observer's right eye). A preferred stereoscopic view is obtained when the
SS spacing is based on a statistical average or mean human eye spacing,
permitting the observer viewing points to generally coincide with the
VVPs. In this simple parallel embodiment, display VVP generator 12P
provides the VVPs by a shift in the value of X along the traverse
coordinate equal to the SS spacing.
The spacing mechanism may be a graphics instruction containing the distance
(or angle) of the SS spacing from the graphics program and stored in the
buffer memory. The spacing mechanism may be spacer 22S which receives a
distance instruction entered through an input device such as keyboard 24K
(see FIG. 2), or otherwise introduced by the observer. Increasing the
spacing increases the observers stereoscopic range perception.
Alternatively, the spacing may be initially defined by a graphics
instruction from the buffer memory, which is subject to change by an
observer entered instruction.
Virtual Viewing Points
An initial VVP mechanism defines the position of an initial virtual viewing
point (initial VVP) 16I for the datamap raster. The initial VVP has an XYZ
position in the three dimensional coordinate system of datamap 10M. The
initial VVP is typically somewhere behind the display screen of monitor
18M, preferably at the vanishing point of the datamap image as shown in
FIG. 1A. First VVP 16L and second VVP 16R also have positions in the three
dimensional coordinate system of datamap 10M. These positions are
typically directly in front of the monitor at a distance point convenient
to the observer as shown in FIG. 1A. Initial VVP 16I may be an instruction
stored in the buffer memory like the initial SS spacing. The initial VVP
may be dynamic and change in response to joystick maneuvers by the
observer (or other input). Alternatively, the initial VVP may be static
(fixed at a set viewing point) or programmed (determined by the graphics
program). A display VVP mechanism provides the first and second VVPs in SS
relationship based on the position of the initial VVP and on the SS
spacing. The display VVP mechanism may be in the source code of the
graphics program, or may be a suitable hardware circuit such as display
VVP generator 12P. In a full shift embodiment (shown in FIG. 1A) first VVP
16L in first channel 10L is initial VVP 16I. Display VVP generator 12P in
the second channel shifts the position of the initial VVP the full SS
spacing along the stereoscopic axis to generate second VVP 16R in SS
relationship with the initial VVP. In a half shift embodiment (shown in
FIG. 2) display vertex generator 24L is in left channel 20L, and display
vertex generator 24R is in second channel 20R. The two VVP generators
shift the initial VVP one half of the SS spacing in the left direction
along stereoscopic display axis 26D to generate left VVP 26L, and one half
of the spacing in the right direction to generate right VVP 26R. In the
simple parallel axis embodiment, the half shifts are simple plus and minus
shifts along the X axis. The half shift embodiment maintains a left/right
balance of the display image relative to the initial VVP centered
therebetween. The balance reduces parallax distortion at near ranges
permitting precision close-up viewing.
Display Vertex Generator 14D
The display vertices may be generated by a suitable hardware circuit such
as display vertex generator 14D located in the first and second channel.
Display vertex generator 14D modifies each datamap vertex in the first
datamap raster to generate a corresponding display vertex in the first
display raster, based on the first VVP and on the range coordinate of that
datamap vertex. Generator 14D similarly modifies each datamap vertex in
the second datamap raster to generate a corresponding display vertex in
the second display raster based on the second VVP and the range
coordinate. The magnitude of the vertex shift is inversely proportional to
the range coordinate of the vertex and directly proportional to the SS
spacing. The vertex shift approaches zero as the range approaches
infinity. The vertex shift at each range for a given spacing may be
provided by a look-up table. In the simple parallel embodiment, each
vertex shift is an X axis displacement of the X coordinate.
Stereoscopic Viewing Device
A stereoscopic viewing device is responsive to the first channel for
presenting the first display raster containing the first display image to
the first eye of the observer. The viewing device is similarly responsive
to the second channel for presenting the second display raster containing
the second display image to the second eye of the observer. The viewing
device may be any suitable stereoscopic device such as display monitor 18M
with shuttered goggles 18G. The monitor alternately displays the first
display image to first viewing window 18L in the goggles, and the second
display image to second viewing window 18R. First viewing window 18L may
be alternately shuttered between a passing mode and a blocking mode, for
passing the first display image to the first eye of the observer and
blocking the second display image. Second viewing window 18R may be
reverse shuttered for blocking the first display image to the second eye
of the observer and passing the second display image. The shuttered
viewing windows may be LCDs having a clear orientation (as shown in window
18L) for passing the display images and having an opaque orientation (as
shown by cross hatching of window 18R) for blocking the display images.
Preferably, the change in LCD orientation is synchronized by SYNC signal
to occur during the inter-raster blank period of the monitor.
The SYNC signal from the graphics processor unit to the viewing device may
be any suitable indicator of raster status such as an EOR SYNC
(end-of-raster signal) shown in FIG. 2. In the embodiment of FIG. 1A, the
shuttered viewing windows are portable goggles worn by the observer. The
SYNC signal is transmitted to the portable goggles by a suitable
transmission medium such as infra-red light. In the embodiment of FIG. 2,
stationary viewing port 28P has left and right shuttered viewing windows
28L and 28R, preferably positioned at left and right VVPs 26L and 26R. The
left and right observer viewing points become fixed at the left and right
VVPs as the observer "fits" into stationary viewing port 28P.
Other monographic image techniques may be employed for establish the SS
relationship from a single monitor such as red/blue images, polarized
images and opticolor glasses. The red/blue technique requires a first
color such as red for the first monographic image, and a second color such
as blue for the second monographic image. The red and blue images may be
presented to the observer simultaneously. The goggles have a red filter
lens for one eye and a blue filter lens for the other eye which separate
the images. Each eye therefore sees only one monographic image. The
polarized technique works on a similar filter basis. The first image is
presented to the first eye polarized along a first axis, and the second
image is presented to the second eye polarized along a second axis shifted
ninety degrees from the first axis. The first and second filters of the
goggles are correspondingly polarized to separate the monographic images
for the observer. The opticolor glasses technique creates a differential
left-right refraction of the colors of a single presented image to
establish a SS relationship. The color (red to blue) of each object in the
presented image is a function of the range (close to remote) of that
object. Longer wavelength light such as red is refracted the most causing
the red portion of the image to appear closer. Shorter wavelength light
such as blue is refracted the least causing the blue portion of the image
to appear farther away. Further details of the opticolor technique are
disclosed in U.S. Pat. No. 4,717,239 and U.S. Pat. No. 5,002,364. The
subject matter of each patent is hereby incorporated by reference in its
entirety into this disclosure.
Polygon Instruction Format
The instruction format for creating triangle polygons 10T is shown in FIG.
1C. The lead instruction starts with a polygon code indicating that this
instruction set defines a datamap polygon. The next code in the lead
instruction defines the number of vertices N forming the polygon. In the
triangle case N=3 (vertex A, vertex B and vertex C). The remaining codes
define various visual aspects of the polygon such as color (if any),
intensity, transparency, and related display information. The next N
instructions are vertex instructions defining the position within the
datamap of each of the N vertices. Each vertex instruction starts with a
vertex code indicating that this instruction defines a vertex, followed by
the X Y and Z coordinates of the position of that vertex within the three
dimensional coordinate system of the datamap. The vertices are defined in
CW sequence or order by the vertex instructions following the polygon
instruction. The three vertex instructions define the three vertices of
triangle 10T.
SEQUENTIAL EMBODIMENT (FIG. 2)
In a still embodiment, the images presented to the stereoscopic viewing
device may be a single pair of stereoscopic images such as one left image
and one right image to present a stereoscopic view of a still scene to the
observer. In a sequence embodiment, a buffer memory provides a sequence of
datamap rasters to graphics processor unit 22 for presenting an animated
image to display monitor 28M. A suitable raster assignor such as raster
alternator 22A assigns every other datamap raster from a buffer memory to
left virtual viewing point generator 22L in left channel 20L forming a
left sequence of display rasters for presentation to the observer's left
eye. The alternate every other datamap raster is assigned to right virtual
viewing point generator 22R in right channel 20R forming a right sequence
of display rasters for presentation to the observer's right eye. The SS
spacing is provided to stereoscopic spacer 22S for determining the left
virtual viewing point (left VVP) 26L and right virtual viewing point
(right VVP) 26R. The display vertex generator in the sequence embodiment
has a left generator 24L in the left channel and a right generator 24R in
the right channel. Left generator 24L generates display vertices in the
left sequence of display rasters. Right generator 24R simultaneously
generates display vertices in the right sequence of display rasters.
Graphics controller 22C controls the operation of the alternator and
generators within GPU 22.
Spacing Over-ride
Stereoscopic spacing over-ride circuit 24S checks the SS spacing between
display rasters in SS relationship by comparing the left VVP position with
the right VVP position. The over-ride circuit replaces the checked spacing
with a default SS spacing whenever the checked spacing exceeds a
predetermined spacing. Action displays in video games frequently have
rapid changes in view point orientation. For instance, the windshield
display for an observer driven vehicle making a hard turn may have severe
VVP displacements between sequential display rasters. A turn over a large
angle may last for several seconds, causing spacing displacements in 100
or so sequential rasters. These displacements will be temporarily greater
than the programmed SS spacing, and may create left/right VVP
discontinuities beyond the observer's to resolve into a stereoscopic view.
The observer may experience dizziness, nausea, headaches and related
trauma associated with simulated motion if these severe displacements are
frequent or of long duration. Replacing severe spacing displacements with
an acceptable default SS spacing, reduces the motion trauma of hard
extended turns.
HEAD MOUNTED EMBODIMENT (FIG. 3)
The stereoscopic viewing device may be a set of head mounted display
monitors such as left front monitor 38L, right front monitor 38R, left
peripheral monitor 39L, and right peripheral monitor 39R as shown in FIG.
3. Left front monitor 38L presents a left front monographic display image
at left virtual viewing point (left VVP) 36L to the left eye of the
observer. Right front monitor 38R presents a right front monographic
display image at right virtual viewing point (right VVP) 36R to the right
eye of the observer. The left and right front images are visually isolated
to maintain the SS relationship permitting direct depth perception. That
is, no part of the left image is included in the right image, and vice
versa. Left peripheral monitor 39L presents a left peripheral display
image to the left periphery of the left eye of the observer, visually
merged with the left front image to provide a monolithic wrap-around left
image. A seamless interface between the front and peripheral images maybe
established by adjustment of the horizontal and vertical position controls
of the monitors. Similarly, right peripheral monitor 39R presents a right
peripheral display image to the right periphery of the right eye of the
observer, visually merged with the right front display image to provide a
wrap-around right image. The front and peripheral images forming each
wrap-around image are not in SS relationship, and do not support direct
peripheral depth perception.
Each monitor has a corresponding channel within graphics processor unit
(GPU) 32 for processing the display images. Left front channel 30L
processes the left front image through left front VVP generator 32L and
left front vertex generator 34L. Right front channel 30R processes the
right front image through right front VVP generator 32R and right front
vertex generator 34R. Left peripheral channel 31L processes the left
peripheral image through left peripheral VVP generator 33L and left
peripheral vertex generator 35L. Right peripheral channel 31R processes
the right peripheral image through right peripheral VVP generator 33R and
right peripheral vertex generator 35R. Shuttered windows are not required
in the head mounted embodiment, because each eye has a separate monitor
which presents only images for that eye. The left and right images are
presented simultaneously on separate monitors. Additional upper and lower
images and channels may be employed in a "fly's eye" embodiment to provide
more complete peripheral vision.
Raster Doubler 32D
The datamap image contained in the datamap raster forming the left front
display raster may be identical to the datamap image contained in the
datamap raster forming the right front display raster. The front image
contain the same display objects at a slightly displaced position to
provide the SS relationship. Raster doubler 32D provides a duplicate
raster to left front channel 30L and to right front channel 30R. Raster
doubling permits a faster three raster cycle into buffer memory 30B. The
three raster cycle has a front raster (which is doubled), a left
peripheral raster and a right peripheral raster. The peripheral rasters
are not doubled because they lack common display objects.
METHOD OF OPERATION (FIG. 4)
In a computer implemented method shown in the flow chart of FIG. 4, a
single monographic datamap image is modified into two monographic display
images in stereoscopic (SS) relationship for presentation to a biocular
observer having a left eye and a right eye. The apparatus required for
carrying out the above method of operation is disclosed hereinbefore in
connection with FIGS. 1A, 1B, 1C, FIG. 2, and FIG. 3. The method may
involve modifying the source code as shown in the source code embodiment
disclosed in FIGS. 5 and 6 hereinafter. The basic steps and sub-steps of
the general method are described below.
Providing a datamap raster containing a datamap image of polygons defined
by polygon vertices from a polygon based graphics datamap. Each vertex has
a position in a three dimensional coordinate system defined by a traverse
coordinate and an elevation coordinate and a range coordinate.
Providing left image channel for processing the datamap raster forming a
left display raster. The left display raster contains a left monographic
image at a left virtual viewing point (left VVP) for presentation to the
left eye of the observer.
Providing right image channel for processing the datamap raster forming a
right display raster. The right display raster contains a right
monographic image at a right virtual viewing point (right VVP) for
presentation to the right eye of the observer.
Defining a stereoscopic (SS) spacing between the left and right VVPs.
Defining the position of an initial virtual viewing point (initial VVP) for
the datamap raster.
Determining the left and right VVPs in SS relationship based on the initial
VVP and on the SS spacing.
Modifying each datamap vertex in the datamap raster to generate a
corresponding display vertex in the left display raster based on the left
VVP and on the range coordinate of that datamap vertex.
Modifying each datamap vertex in the datamap raster to generate a
corresponding display vertex in the right display raster based on the
right VVP and on the range coordinate of that datamap vertex.
Presenting the left display raster containing the left monographic image to
the left eye of the observer in a left presentation mode.
Presenting the right display raster containing the right monographic image
to the right eye of the observer in a right presentation mode, which is
distinguishable from the left presentation mode. The right monographic
image is in SS relationship with the left monographic image.
The step of presenting the display rasters to the observer may include
distinguishing the left presentation mode from the right presentation mode
through a stereoscopic viewing device.
The step of distinguishing the presentation modes may include shuttering
the stereoscopic viewing device for alternately passing and blocking the
left and right images. First the shuttering passes the left image in the
left presentation mode to the left eye of the observer while blocking the
right image in the right presentation mode. Then the shuttering blocks the
left image in the left presentation mode while passing the right image in
the right presentation mode to the right eye of the observer while.
The computer implemented method may involve a computer readable medium
containing a computer program that modifies the single monographic datamap
image into the two monographic display images. The step of defining the SS
spacing may be an instruction executed within the source code of the
computer program. The step of defining the left and right VVPs may be
executed within the source code of the computer program by alternating a
set VVP instruction. In one embodiment, the set VVP instruction may be
modified between the initial VVP and either the left VVP or the right VVP.
In which case, one eye of the observer has the initial VVP, and the other
eye has the modified VVP. In another embodiment, the set VVP instruction
is modified between the left VVP and the right VVP. In this case, the left
eye has the left VVP, and the right eye has the right VVP. Neither the
initial datamap image nor the initial VVP are presented to the observer.
SOURCE CODE METHOD (FIGS. 5, 6A and 6B)
The general flow chart of FIG. 5 shows the modification of the initial
monographic source code (and object code) into new stereoscopic source
code (and object code). The initial monographic object code containing the
monographic image is dis-assembled into initial monographic source code.
The source code is read one instruction at a time. Each instruction is
examined for an initial viewpoint location set command. If the instruction
contains a VP command (YES), a new instruction is inserted for
stereoscopic conversion into new source code. The new stereoscopic source
code is recompiled to stereoscopic object code for use in computer
apparatus figures. If the instruction does not contain a VP command (NO),
the instruction is examined for an EOF (end-of-file) flag, and processed
as required. The resulting change in the source code is shown in FIGS. 6A
and 6B. The initial source code listing (FIG. 6A) contains codes required
to generate monographic display rasters at a single viewing angle. The new
source code listing (FIG. 6B) shows an added code for alternating the
viewing angles to provide alternate display rasters in stereoscopic
relationship.
INDUSTRIAL APPLICABILITY
It will be apparent to those skilled in the art that the objects of this
invention have been achieved by providing multiple monographic images in
stereoscopic relationship which support direct perception of range. The
stereoscopic spacing of the stereoscopic relationship is controlled by
program or observer inputs for enhancing the range perception. In some
embodiments, left/right shuttering of the monographic images is provided
to isolate the left and right images for the observer. In another
embodiment, head mounted monitors present the monographic images to the
observer, fixing the left and right VVPs relative to the left and right
eyes of the observer. The head mounted monitors also provide front images
and peripheral images in wrap-around relationship for promoting the
observer's sense of immersion into the image.
CONCLUSION
Clearly various changes may be made in the structure and embodiments shown
herein without departing from the concept of the invention. For example,
both still images and sequential images may be employed in the portable
embodiment, the stationary embodiment, and the head mounded embodiment.
Further, features of the embodiments shown in the various figures may be
employed with the embodiments of the other figures.
Therefore, the scope of the invention is to be determined by the
terminology of the following claims and the legal equivalents thereof.
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