Faculty of Forest, Geo and Hydro Sciences, Department of Geosciences, Institute for Cartography
Bases modernas de visualización de geodatos y visualización de geodatos y Visualización tridimensional de geodatos
Prof. Dr. Manfred F. BuchroithnerTU Dresden, Institute for CartographyTU Dresden, Institute for Cartography
The Third Dimension
Content
0. Motivation
1 The Third Dimension in our Environment1. The Third Dimension in our Environment
2. The Third Dimension in a Map – Current State
3. Perception of the Third Dimension
4. Creation of Three-Dimensional Geometry Data
5. Possibilities of 3D-Visualisation: Pseudo-3D
6. Possibilities of 3D-Visualisation: True-3D
1 November 2011 3Visualización tridimensional de Geodatos
0. Motivation
Let‘s have a look at topographic maps! …
Rocky Mountain National Park;© T il ill t t d
Wooded coverage
1 November 2011
© Trails illustrated4Visualización tridimensional de Geodatos
0. Motivation(2/8)(2/8)
0. Motivation (2)
© Kargel W Die Bergwelt Rumäniens“
1 November 2011
© Kargel, W. „Die Bergwelt Rumäniens
5Visualización tridimensional de Geodatos
1 November 2011 6Visualización tridimensional de Geodatos
0. Motivation(4/8)(4/8)
Landscape Aesthetics and Relief
Relief aesthetics:• They attempt to quantify the aesthetic value of the relief of a landscape.• Close connexion with relief intensity (German: Reliefenergie)
Upcoming questions:Upcoming questions:• To what degree determines the relief intensity of a landscape the possible
aesthetics of a map?• How does the manner of relief representation in a map bias the aesthetic
appearance of the latter?
1 November 2011 7Visualización tridimensional de Geodatos
0. Motivation(5/8)(5/8)
Landscape Aesthetics and Relief (2)
Investigations:“Classical monographs”:• Roger Crofts (1975): ”The Landscape Component Approach to Landscape
Evaluation” • Steven Bourassa (1991): “The Aesthetics of Landscape”Steven Bourassa (1991): The Aesthetics of Landscape• Allen Carlson (2007): “Teaching environmental aesthetics”• …
An optimum visualisation of the relief certainly helps to generate a “mental 3D map”
► Lenticular foil displays
1 November 2011 8Visualización tridimensional de Geodatos
0. Motivation(6/8)(6/8)
Landscape Aesthetics and Relief (3)
• Systematic study of landscape art, design and education• Examples:
– Paintings of mogotes of Guilin, China– Ludwig Richter’s paintings of Saxon Switzerland, Bohemian Low Mountain
Range etc.
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9Visualización tridimensional de Geodatos
0. Motivation(6/8)(6/8)
Landscape Aesthetics and Relief (3)
• Systematic study of landscape art, design and education• Examples:
– Paintings of mogotes of Guilin, China
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1 November 2011
10Visualización tridimensional de Geodatos
0. Motivation(6/8)(6/8)
Landscape Aesthetics and Relief (3)
• Systematic study of landscape art, design and education• Examples:
– Paintings of mogotes of Guilin, China– Ludwig Richter’s paintings of Saxon Switzerland, Bohemian Low Mountain
Range etc.
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11Visualización tridimensional de Geodatos
0. Motivation(7/8)(7/8)
Landscape Aesthetics and Relief (4)
• Is an aesthetic landscape also considered attractive?
• Human aesthetic perception is a result of evolutionary adaptation:– Anything serving the survival and the reproduction = attractive
(e.g. natural rock roofs, abris or caves, or places appropriate for (e.g. natural rock roofs, abris or caves, or places appropriate for – cave digging) – Totally flat landscapes are mostly not so attractive.
– Relief water survival
► Relief has always been attractive.
1 November 2011 12Visualización tridimensional de Geodatos
0. Motivation(8/8)(8/8)
► Truly three-dimensional geo-embodiments have a high degree of
Landscape Aesthetics and Relief (5)
► Truly three dimensional geo embodiments have a high degree of attractiveness and probably also a higher user acceptance than „flat” geo-displays like colourful maps or colour photographs.
► Desirable is the development of methods which enable the map reader to t l i th li f i f ti ith th id d i spontaneously perceive the relief information with the unaided eyes, i.e.
without the use of either anaglyph glasses, chromadepth glasses, or polarisation glasses, i.e. autostereoscopically.
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1 November 2011 13Visualización tridimensional de Geodatos
1. The Third Dimension in our Environment
Restriction to third dimension Height coordinate of the relief
Important because of the „Topographic Resistance“:• Terrain opposes resistance to human actions• Barrier effects can not be justified only by height • Barrier effects can not be justified only by height,
e.g. separation effect of waters, swamps
T hi l R i t i ti bl bTopographical Resistance is noticeable by:• Traffic / Tourism• Settlement• Cultivation
1 November 2011 14Visualización tridimensional de Geodatos
1. The Third Dimension in our Environment(2/5)(2/5)
Relief and Terrain
Relief: Entirety of continental and oceanic respectively submarine shapes of the surface of the earth and of other planets; Part of the terrain
f(translated from: Lexikon der Kartographie und Geomatik, Spektrum Verlag, 2002)
Relief Relief: Described by dataset of infinitely dense xyz coordinate triplets.(according to Buchroithner)
Terrain: Relief and surface cover(according to Buchroithner)(according to Buchroithner)
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1. The Third Dimension in our Environment(3/5)(3/5)
Calculation of relief
Interpretation of Relief Data
Calculation of relief facets from the DTM
Catchments Uimon Steppe and Katun Tributary Valleys
Flow gradient Uimon Steppe and Katun Tributary Valleys
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1. The Third Dimension in our Environment(31/5)(3 /5)
Calculation of relief
Interpretation of Relief Data
Calculation of relief facets from the DTM
1 November 2011 17Visualización tridimensional de Geodatos
1. The Third Dimension in our Environment(32/5)(3 /5)
Interpretation of Relief Data
Catchments Uimon Steppe and Katun Tributary Valleys
1 November 2011 18Visualización tridimensional de Geodatos
1. The Third Dimension in our Environment(33/5)(3 /5)
Interpretation of Relief Data
Flow gradient Uimon Steppe and Katun Tributary Valleys
1 November 2011 19Visualización tridimensional de Geodatos
1 November 2011 20Visualización tridimensional de Geodatos
1 November 2011 21Visualización tridimensional de Geodatos
2. The Third Dimension in a Map – Current State
fl d l d d l d d d h
Term „Map“
Maps are flattened, scaled-down, generalised and commented cartographic representations of natural and social topics of the earth, …(from: International Dictionary of Cartographic Terms)
– Diminution vs. Minimal sizes
G li ti l t li i t – Generalisation: select, eliminate, merge
– Explanation: decoding help, symbolisation, classification
1 November 2011 22Visualización tridimensional de Geodatos
2. The Third Dimension in a Map – Current State(2/2) (2/2)
Function of a Map
• Orientation guide– Positioning of thematic
information
• Data storage
information– Navigation aid
• Basis for discussion– Public participation– Information panels
• Decision „carrier“– Planning
Route selection
p
– Route selection
1 November 2011 23Visualización tridimensional de Geodatos
f3. Perception of the Third Dimension
• Stereoscopic vision is learned in infancy (unconsciously)• Perception of spatial relationships is based on phenomena which can be
monocular or binocular (psychological vs. physiological depth cues)• Spatial perception is a „process“ in (at least) two steps:
– image detection (eye[s])g ( y [ ])– image interpretation (visual centre of the brain)
H ti l ti i i d t ti i i t t ti Human spatial perception is image detection, -processing, -interpretation. The quality of visual detection determines the spatial perception. Geometry is only indirectly captured by image differences (pattern, colour,
brightness). Thus: high frequency, accurately fitting image data required!
1 November 2011 24Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (2/12)(2/12)
From Natural to Artificial Stereoscopic Vision
• Spatial perception is based on 10 major parameters, the depth cues.• Monocular or binocular depth cues
physiological psychological
retinal disparity retinal image size
convergence linear perspective
accomodation aerial perspective accomodation aerial perspective
motion parallax occlusion/overlapping
( h i ) h d i (ill i i ) (chromostereopsis) shadowing (illumination)
texture gradient
1 November 2011 25Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (3/12)(3/12)
Relief Representation in a Map
Relief representation in cartography has always been challenging.
Some approaches:pp
• Hypsometric colouring– Attention: land-cover vs. height– Haze effects: “aerial perspective”
• Illumination effects / shading – Oblique light hill shading– Oblique light hill shading– Slope hachures / slope shading – Combination of both
• Consideration of “land-cover”
1 November 2011 26Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (4/12)(4/12)
Monocular Spatial Perception
• It is also possible to receive a certain spatial impression with only one eye: The observer relies on clear visual structures (depth cues):– Occlusion– Knowledge regarding the relation of proportions and/or scales and
distances– Motion perception – “Haze effect“
1 November 2011 27Visualización tridimensional de Geodatos
3. Wahrnehmung der dritten Dimension(5/14)(5/14)
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1 November 2011 30Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (8/12)(8/12)
• irregular grid of points with
Contour Line Drawing
• irregular grid of points with known height
• Interpolation of contour lines• Contour line displacement • Contour line displacement
because of other map elements or of adjacent contour lines at a too steep
l f l !angle of slope!
Example: Argut (Altai Mountain, Russia)Russia)
Contour lines are a tool for the visualisation of the relief
Modifications can be assumed from the context
1 November 2011 31Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (9/12)(9/12)
Relief Perception by the Map User
• More than 60% of all users of topographic or hiking maps and are not able to
derive the relief information spontaneously (studies carried out in the 1970s
and the 1980s; participants: members of alpine climbing courses with
academic education).
• Studies from 1992, 1997 and 2006 in 16 visitor centres of national parks and
national monuments of the western U S A and of Iceland with 909 national monuments of the western U.S.A. and of Iceland with 909
participants revealed that a varying percentage of 67 to 100 % of the visitors
of the information centres spontaneously headed for the solid terrain models
as soon as they had “discovered” them, even if interesting maps were around.
1 November 2011 32Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (10/12)(10/12)
Spatial Perception (1)
Natural stereoscopic viewing:• b: eye base (= 6,5 cm)• γ, γ‘: convergence angle• δ = γ‘ – γ = angular parallax• δmax = 1°
Artificial stereoscopic viewing:• Single images („stereomates“):
stereomatesSingle images („stereomates ):
• Discrete perception of the left and the right stereomate
• Different perspective• Different perspective• Nearly same content
1 November 2011 33Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (101/12)(10 /12)
Spatial Perception (1)
Natural stereoscopic viewing:• b: eye base (= 6,5 cm)• γ, γ‘: convergence angle• δ = γ‘ – γ = angular parallax• δmax = 1°
Artificial stereoscopic viewing:• Single images („stereomates“):
stereomatesSingle images („stereomates ):
• Discrete perception of the left and the right stereomate
• Different perspective• Different perspective• Nearly same content
1 November 2011 34Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (102/12)(10 /12)
Spatial Perception (1)
Natural stereoscopic viewing:• b: eye base (= 6,5 cm)• γ, γ‘: convergence angle• δ = γ‘ – γ = angular parallax• δmax = 1°
Artificial stereoscopic viewing:• Single images („stereomates“):
stereomatesSingle images („stereomates ):
• Discrete perception of the left and the right stereomate
• Different perspective• Different perspective• Nearly same content
1 November 2011 35Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (103/12)(10 /12)
Spatial Perception (1)
Natural stereoscopic viewing:• b: eye base (= 6,5 cm)• γ, γ‘: convergence angle• δ = γ‘ – γ = angular parallax• δmax = 1°
Artificial stereoscopic viewing:• Single images („stereomates“):
stereomatesSingle images („stereomates ):
• Discrete perception of the left and the right stereomate
• Different perspective• Different perspective• Nearly same content
1 November 2011 36Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (104/12)(10 /12)
Spatial Perception (1)
Natural stereoscopic viewing:• b: eye base (= 6,5 cm)• γ, γ‘: convergence angle• δ = γ‘ – γ = angular parallax• δmax = 1°
Artificial stereoscopic viewing:• Single images („stereomates“):
stereomatesSingle images („stereomates ):
• Discrete perception of the left and the right stereomate
• Different perspective• Different perspective• Nearly same content
1 November 2011 37Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (11/12)(11/12)
Spatial Perception (2)
• Human beings can only see images intuitively and directly but not perceive the geometry as such.
► Spatial impression dependent on the observation of differences in intensity ► Spatial impression dependent on the observation of differences in intensity, hue, saturation and illumination effects (e.g. shadow)
• Terms for aesthetic visual perception:
– no stress and strain to the eyes,
no unpleasant or tiring illumination conditions– no unpleasant or tiring illumination conditions,
– not any other significant impediment and objection,i.e. no glasses or other viewing aids,
– aesthetic radiation or vibrancy of the scene per se.
► Lenticular foil displays seem to be the means of choice.
1 November 2011 38Visualización tridimensional de Geodatos
3. Perception of the Third Dimension (12/12)(12/12)
Spatial Perception (3)
• Stereoscopy vs. object reconstruction:
► Stereomates provided to the human’s eyes vs. Viewing of a three-dimensional model (e.g. STM, stereo lithography, holography)
• Autostereoscopy:
► Spontaneously spatial perception without additional viewing means
1 November 2011 39Visualización tridimensional de Geodatos
C i f h di i l G4. Creation of Three-dimensional Geometry Data
Relief Data
• Digital terrain model (DTM)
Relief Data
• Digital terrain model (DTM)
• Usually: flat grid of height valuesF h di t i l h i ht- For each xy-coordinate pair only one height
- As an attribut- Thus: only “2.5D”
• Grid of height values- Xyz-coordinate triplety p
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4. Creation of Three-dimensional Geometry Data (2/8)(2/8)
Relief Data
1 November 2011 41Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (3/8)(3/8)
Examples for the Generation of Relief Data
a) Shuttle Radar Topography Mission – SRTM) p g p y
© Dornier Satellitensysteme / EADS 01/00
1 November 2011
© Dornier Satellitensysteme / EADS 01/00
42Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (4/8)
Technische Daten HRSC
(4/8)
Brennweite 175 mm IFOV 2.0 mrad Anzahl der CCD-Zeilen 9 ut
ion
ra
Aktive Pixel pro CCD-Zeile 5184 Pixelgröße 7 µm Stereowinkel ±12,8°, ±18,9°
fh Res
ol C
amer
Radiometrische Auflösung 8 bit Auslesefrequenz 450 lines/sec Masse des Systems 24 kg
b) H
igh
Ste
reo
CCD-Zeile
Band Filter Wellenlänge (nm)
Bandbreite (nm)
Stereo- winkel(°)
5F (SF) Stereo Panchromatisch 675±90 180 18,9 4F (Rd) R t F R t 750±20 40 15 94F (Rd) Rot Fernes Rot 750±20 40 15,9 3F (PF) Photometrie Panchromatisch 675±90 180 12,8 2F (Bl) Blau Blau 440±45 90 3,3
1N (ND) Nadir Panchromatisch 675±90 180 0 Ber
lin
2A (Gr) Grün Grün 530±45 90 3,3 3A (PA) Photometrie Panchromatisch 675±90 180 12,8 4A (IR) Nahes Infrarot Infrarot 970±45 90 15,9 5A (SA) Stereo Panchromatisch 675±90 180 18 9 ©
DLR
/FU
B
1 November 2011
5A (SA) Stereo Panchromatisch 675±90 180 18,9
©
43Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (5/8)(5/8)
c) Laser Scanner
Dachstein Southface Cave
Riegl LMS Z420i laser-scanner Ramsau Dome
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4. Creation of Three-dimensional Geometry Data (6/8)(6/8)
Data Requirements for Stereo Visualisation
Human spatial perception is image detection, -processing, -interpretation:
The quality of visual detection determines the spatial perception.q y p p p
Geometry is only indirectly captured by image differences (pattern, color, brightness). Thus, "simple" topographic map is not suitable as a texture!
The fitting accuracy of texture and geometry is inversely proportional to the potential fatigue respectively to the effort of the viewer. ( i l li i i d )(Virtual Reality: immersion degree)
Perception is influenced by areas of bad conditions between fall of ground andillumination conditionsillumination conditions.
1 November 2011 45Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (7/8)(7/8)
Data Requirements for Stereo Visualisation
1 November 2011 46Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (71/8)(7 /8)
Data Requirements for Stereo Visualisation
1 November 2011 47Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (72/8)(7 /8)
Data Requirements for Stereo Visualisation
1 November 2011 48Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (8/8)(8/8)
Quality assurance
Data Requirements for Stereo Visualisation
Quality assurance is required, if the geometry and texture data is not texture data is not captured synchronously!
Example:Mt. Everest, IKONOS data on IKONOS data on conventionally observed terrain modelmodel
1 November 2011 49Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (81/8)(8 /8)
Data Requirements for Stereo Visualisation
Quality assurance Quality assurance is required, if the geometry and texture data is not texture data is not captured synchronously!
Example:Mt. Everest, IKONOS data on IKONOS data on conventionally observed terrain modelmodel
1 November 2011 50Visualización tridimensional de Geodatos
4. Creation of Three-dimensional Geometry Data (82/8)(8 /8)
Data Requirements for Stereo Visualisation
Quality assurance Quality assurance is required, if the geometry and texture data is not texture data is not captured synchronously!
Example:Mt. Everest, IKONOS data on IKONOS data on conventionally observed terrain modelmodel
1 November 2011 51Visualización tridimensional de Geodatos
ibili i f 3 i li i d 35. Possibilities of 3D-Visualisation: Pseudo-3D
T e colo image and te ain model f om one came aTrue colour imagery and terrain model from one camera
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5. Possibilities of 3D Visualisation: Pseudo-3D(2/5)(2/5)
Hillshading – Illumination Simulation
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5. Possibilities of 3D-Visualisation: Pseudo-3D(21/5)(2 /5)
Hillshading – Illumination Simulation
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5. Possibilities of 3D-Visualisation: Pseudo-3D(22/5)(2 /5)
Hillshading – Illumination Simulation
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5. Possibilities of 3D-Visualisation: Pseudo-3D(23/5)(2 /5)
Hillshading – Illumination Simulation
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5. Possibilities of 3D-Visualisation: Pseudo-3D(3/5)
h d ll l l ll h d
(3/5)
In general:
High-End Illumination Simulation: Colour Hillshade
In general:• monochrome shading (not
necessarily greyscale)only one direction of • only one direction of illumination
• local light rotations necessarynecessary
New: combination of two or three illumination or three illumination directions with different primary colours.
DTMMOLA
ImageMOC+ = Colour Shading
1 November 2011
MOLA MOC
57Visualización tridimensional de Geodatos
5. Possibilities of 3D-Visualisation: Pseudo-3D(31/5)
h d ll l l ll h d
(3 /5)
In general:
High-End Illumination Simulation: Colour Hillshade
In general:• monochrome shading (not
necessarily greyscale)only one direction of • only one direction of illumination
• local light rotations necessarynecessary
New: combination of two or three illumination or three illumination directions with different primary colours.
DTMMOLA
1 November 2011
MOLA
58Visualización tridimensional de Geodatos
5. Possibilities of 3D-Visualisation: Pseudo-3D(32/5)
h d ll l l ll h d
(3 /5)
In general:
High-End Illumination Simulation: Colour Hillshade
In general:• monochrome shading (not
necessarily greyscale)only one direction of • only one direction of illumination
• local light rotations necessarynecessary
New: combination of two or three illumination or three illumination directions with different primary colours.
DTMMOLA
ImageMOC+
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MOLA MOC
59Visualización tridimensional de Geodatos
5. Possibilities of 3D-Visualisation: Pseudo-3D(33/5)
h d ll l l ll h d
(3 /5)
In general:
High-End Illumination Simulation: Colour Hillshade
In general:• monochrome shading (not
necessarily greyscale)only one direction of • only one direction of illumination
• local light rotations necessarynecessary
New: combination of two or three illumination or three illumination directions with different primary colours.
DTMMOLA = Colour ShadingImage
MOC+
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MOLA MOC
60Visualización tridimensional de Geodatos
5. Possibilities of 3D-Visualisation: Pseudo-3D(4/5)(4/5)
Map Production
© OeAV
HRSC DTM visualised by SCOP++
1 November 2011
HRSC-DTM, visualised by SCOP++
61Visualización tridimensional de Geodatos
5. Possibilities of 3D-Visualisation: Pseudo-3D(5/5)(5/5)
Example: Granatspitzgruppe, Austria
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6 ibili i f 3 i li i 36. Possibilities of 3D-Visualisation: True-3D
Classification:Classification:
• Regarding the 3D effect:– Parallax-3D (parallax in the direction of the eye axis)(p y )– Full-3D (parallax in all directions of the image plane)– Haptic (relief models)
• Regarding the perception: – Non-autostereoscopic– Autostereoscopic
• Regarding the number of stereomates:– 1 stereomates– 2 stereomates2 stereomates– At least 2 or more stereomates
More information about the true-3D-visualisation: See the following sections!
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63Visualización tridimensional de Geodatos