Lec 7 Virtual Reality
description
Transcript of Lec 7 Virtual Reality
1 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
Data Analysis and VisualizationIntroduction to Virtual Reality and Immersive Visualization
Benjamin Weyers
2 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
2
One Minute Paper – Positive Feedback
• Good Examples IIIIIII (7)• Clear English IIII (4)• Good slides IIII (4)• Humorous II (always tries (!) to make jokes) (2)• Man kann alle Inhalte verstehen II (2)• Really nice lecture II (2)• Sum up at the end of each part• Bester Vortrag seit 2 Jahren studieren, hat mich voll motiviert das Fach zu rocken. Freue
mich auf Dezember • Folien sind sehr übersichtlich• Interessante Vorlesung mit Selbsexperiment• Gutes Tempo • Good structure• Viele Bilder• Sehr interessant und anschaulich• Science Applications
3 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
3
One Minute Paper –Negative Feedback
• Show real application examples (Google Cardboard, 3D Rendering software) III (3)• Somewhat quiet III (3) -> Microphone• Voice modulation helps to get human attention II (2)• Nicht immer klar was wichtig / klausurrelevant ist II (2)• Inhalte veraltet II (2)• Nothing II (2)• More programming exercise -> Next Exercises on Web-based InfoVis• Include some assignment / project for rendering• Formeln werden nicht erklärt• Use MatLab to show operations• Not going to deeply into topics• Mathematical Notation: v*M bad, M*v good• I didn‘t get the concept of the first two lectures• Folien übersprungen• Luminance and Brightness: Difference? • Too long• Vague objective of the course
4 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
4
Perception
Closer look to (Visual) Analysis in the Simulation Loop
Simulation
Visualization
ScientificVisualization
InformationVisualization
Rendering
User
f: Δ ‐> R
RAW DATA
VIS DATAIMAGE DATA
5 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
5
Introduction - Topics
• What is Virtual Reality?
• VR Displays and Systems
• Stereoscopic, Viewer-Centered Projections
• VR in Scientific Visualization
6 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
6
Why Data Analysis & Visualization?
• Generating insight from data requires data analysis.Hamming: „The purpose of Computing is insight, not numbers!“
JUQUEEN IBM Blue Gene/Q System, JSC, Forschungszentrum Jülich GmbH
110111101101011010101111011011101010101110110
101…001010010100111110100101010101001010111010101
1010111100…010010101001010101001010101010010101110101011
010111100…
raw dataGigabyte-Terabyte-Petabyte
7 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
7
Why Data Analysis & Visualization?
• Generating insight from data requires data analysis.Hamming: „The purpose of Computing is insight, not numbers!“
• Visualization is (primarily) being used for the analysis process
110111101101011010101111011011101010101110110
101…001010010100111110100101010101001010111010101
1010111100…010010101001010101001010101010010101110101011
010111100…
raw dataGigabyte-Terabyte-Petabyte VisualizationJUQUEEN IBM Blue Gene/Q System, JSC,
Forschungszentrum Jülich GmbH
Filtering Mapping Rendering
8 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
8
Why Data Analysis & Visualization?
• Generating insight from data requires data analysis.Hamming: „The purpose of Computing is insight, not numbers!“
• Visualization is (primarily) being used for the analysis process• Amount of raw data is rapidly increasing: Finer grids, 3-D, time-variant• Explorative versus confirmative analysis, Virtual Reality
110111101101011010101111011011101010101110110
101…001010010100111110100101010101001010111010101
1010111100…010010101001010101001010101010010101110101011
010111100…
raw dataGigabyte-Terabyte-PetabyteJUQUEEN IBM Blue Gene/Q System, JSC,
Forschungszentrum Jülich GmbH
9 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
9
Introduction – Topics
• What is Virtual Reality?
• VR Displays and Systems
• Stereoscopic, Viewer-Centered Projections
• VR in Scientific Visualization
10 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
10
Virtual Reality – A Definition
Virtual Reality (VR) is a computer generated environment. A user can interact with this environment and experience it with her
natural senses.
11 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
11
What is Virtual Reality about?
• Navigation• Manipulation
… in real-time!
• 3-D & multimodal• visual• acoustic• haptic/tactile• proprioceptive
IMMERSION
IMAGINATIONINTERACTION
I³
12 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
12
3D Vision: Physiological & Psychological Cues
Traditional CG:• Psychological clues Perspective shortening Occlusion of objects Light and shadows Texture gradients Atmospheric perspective
13 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
13
Perspective
Drawing: Goldstein (WWW)
14 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
14
The Ames Room
Pictures: Goldstein, Levine & Shefner (WWW)
https://upload.wikimedia.org/wikipedia/commons/1/11/Ames_room.ogv
15 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
15
Occlusion
Pictures: Hübner (WWW)
16 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
16
Light & ShadowsPictures: Levine & Shefner (WWW)
17 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
17
3D Vision: Physiological & Psychological Cues
Traditional CG:• Psychological clues Perspective shortening Occlusion of objects Light and shadows Texture gradients Atmospheric perspective
Virtual Reality:• Physiological clues Stereopsis Ocular motor factors Accommodation Convergence
Motion parallax
18 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
18
ConvergenceDrawing: Goldstein (WWW)
19 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
19
Accommodationhttp://www.denstoredanske.dk
20 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
20
Motion Parallax
Tom Vaughan,www.cyberlink.com
21 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
21
Motion Parallax
22 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
22
Stereopsis
• Interocular distance (about 6 cm)• Disparity of images projected onto the retina• Processing in the visual cortex of the brain• Works for distances up to 7 m
http://www.more3d.com/3‐D/Stereoskopie.html
23 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
23
Depth Cue Scope Classification Position Estimation
Occlusion full range mono‐ocular relative
Disparity < 10m bi‐ocular relative
Convergence < 2m bi‐ocular absolut
Accomodation < 2m mono‐ocular absolut
Image Blur full range mono‐ocular relative
Linear Perspective full range mono‐ocular absolut
Texture Gradient full range mono‐ocular relative
Relative Size full range mono‐ocular absolute
Known Size full range mono‐ocular absolute
Height in Visual Field > 30m mono‐ocular relative
AtmosphericPerspective
> 30m mono‐ocular relative
Shape from Shading full range mono‐ocular relative
Shadows full range mono‐ocluar relative
Motion Parallax > 20m dynamic relative
Accretion full range dynamic relative
24 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
24
Introduction – Topics
• What is Virtual Reality?
• VR Displays and Systems
• Stereoscopic, Viewer-Centered Projections (VCP)
• VR in Scientific Visualization
25 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
25
The Head Mounted Display
Pictures: diverse Web Sites
I. Sutherland
CAE
Sony
BOOM
Retina Display, Microvision
26 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
26
Head-Mounted Displays versus Stereo Glasses
Until 1994: VR = HMD + Instrumented Glove Stereo Glasses (here: Shutter)
27 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
27
Stereo Parallax in Room-Mounted Displays
Tom Vaughan,www.cyberlink.com
28 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
28
Stereograms
zero parallax non-crossed(positive) parallax
crossed(negative) parallax
29 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
29
Stereo Glasses: Shutter (“Active Stereo”)
• Time Multiplex• Genlocking of multiple graphics hardware
Infrared Stereo Emitter: Synchronization of glasses and graphics hardware
Shutter Glasses with markers for opto-electronical tracking
30 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
30
Stereo Glasses: Shutter (“Active Stereo”)
31 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
31
Stereo Glasses: Polarization (“Passive Stereo”)
• Linear or circular polarization• Swap (and Frame) locking of multiple graphics hardware• screen material may not destroy polarization (hot spot)
32 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
32
Distortions in Static Stereograms
33 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
33
Adaptation of projection to the viewpoint
34 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
34
Electromagnetic Tracking - Polhemus
35 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
35
Electromagnetic Tracking in Military
36 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
36
Electromagnetic Tracking – Pros & Cons
+Position & orientation+No occlusion- sensitive to ferromagnetic materials in the environment- Accuracy decreases with growing distance between sender and
receiver - Rather large sensors (1-2 cm)
37 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
37
Optoelectronic Tracking – A.R.T.Picture: A.R.T. GmbH
38 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
38
Optoelectronic Tracking – Pros & Cons
+ Accuracy, latency sample rate (of today’s systems)+ Passive markers: No cabling, nearly non-intrusive- Occlusion- No orientation (combine 3 non-collinear markers)- Calibration process (rather comfortable in today’s systems)
39 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
39
The Principle of Viewer Centered Projection (VCP)
stereo parallax motion parallax
40 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
40
Diagonal Projection
nearclipping plane
viewing window farclipping planeeye position
(viewpoint)
Front Clippling Plane(Near)
Far Clippling Plane(Far)
x/y
z
left/top
Right/bottom
Here:• Origin in the míddle of the scre• Z‐axis perpendicular to screen
Eyepoint E
41 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
41
Basic Operations
or
or
42 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
42
Shearing of the View Volume
43 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
43
The Projection Matrix
Parameters:• Position of the view window: left, right, top, bottom• Near and far clipping plane: near, far• Eye position E
44 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
44
Viewer Centric Projection (VCP) on a Workbench
45 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
45
Effect of Motion Parallax
Courtesy of Bill Sherman
46 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
46
3D Vision: Physiological & Psychological Cues
Traditional CG:• Psychological clues Perspective shortening Occlusion of objects Light and shadows Texture gradients Atmospheric perspective
Virtual Reality:• Physiological clues Stereopsis Ocular motor factors Accommodation Convergence
Motion parallax
47 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
47
PowerWall
Analysis of forming processes on a PowerWall(IBF and RZ, 2000)
48 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
48
Stereo Glasses: Polarization (cont.)
49 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
49
Multi Projector PowerWall
Picture: Burdea et al.
Pictures: Panoram Technologies, Indeed Visual Concepts
50 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
50
High Resolution PowerWall @ AICES Graduate School
4096 pixels
2160
pix
els
51 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
51
The CAVE, 1993
CarolinaCruz‐Neira
52 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
52
CAVE Installations in Germany in 2004
• Front, back, left, right, bottom, top
• Front, left, right, bottom, top
• Front, back, left, right, bottom
• Front, left, right, bottom
• Front, left, bottom
• Front, left, right
Research Institutes• Stuttgart, Fraunhofer IAO/IPA (6)• Bonn caesar (7)• Darmstadt, Fraunhofer IGD (5)• Magdeburg, Fraunhofer IFF (5)• Berlin Fraunhofer IPK (5)• Berlin Fraunhofer First (5)• St. Augustin Fraunhofer IMK (4)• Braunschweig DLR (3)
Industry• München, BMW (4)• Sindelfingen, DaimlerChrysler (5)• Ulm, DaimlerChrysler (4)• Wolfsburg, VW (3) University• Aachen RWTH, RZ (5)• Bielefeld Univ. AG KI (3)• Chemnitz, TU (5)• Stuttgart Univ., HLRZ (4)(2004, maybe incomplete)
53 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
53
The aixCAVE @ RWTH Aachen
Same visual perception in real & virtual world!Realize stereo ANDmotion parallax
54 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
54
PC Clusters for Immersive Displays
55 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
55
The aixCAVE Specs
• Footprint approx. 5.50 x 5.50 m, 3,30 m high• 24 WUXGA Active Stereo Projectors
• Approx. 3200 x 2000 pixels per wall• Approx. 3600 x 3600 Pixels at the floor• Brightness: Nearly 300.000 ANSI Lumen
56 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
56
VCP in the aixCAVE
57 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
57
Topics
• What is Virtual Reality?
• VR Displays and Systems
• Stereoscopic, Viewer-Centered Projections
• VR in Scientific Visualization
58 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
58
VR Applications in CES @ RWTH
• Motors & Turbines• Twin Extruders• Nasal Airflow• Bood Flow• Crash Simulations• Material Science• Pig housing
AIA, FEV GmbH, VR Group DLR, IST, VR Group
IKV, VR GroupCATS, VR GroupAIA, VR Group
59 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
59
Video: Counter Propfan
L. Jerabkova
60 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
60
Motivation
SMP Cluster in Aachen
Challenges • Performance: Interactivity versus large datasets• HCI: How to create and interact with complex vis objects in 3D?
How to navigate in space and time?
JUQUEEN IBM Blue Gene/Q System, JSC, Forschungszentrum Jülich GmbH
Increasing Computer Power
Comples Simulations(3D, fine grids, unsteady
Explorative (instead of confirmative) analysis in 3-D space
• Trial & Error process• Interactivity!
61 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
61
Levels of Interactivity
• What is interactive? Nothing Image, Animation (Movie)
Rendering only Navigation, selection & animation of pre-computed vis. primitives
Filtering, Mapping, Rendering Interactive Visualization, Interactive Post Processing, Explorative Analysis
Simulation, Filtering, Mapping, Rendering Interactive Simulation, Computational Steering,
Interactive Supercomputing, Human-In-the-Loop
Simulation Filtering RenderingMapping Display
Raw Data Vis. Primitives Graphics Primitives Pixels
62 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
62
Architecture for VR-based Scientific Visualization
Dilemma: Interactivity versus large datasets
Raw Data Postprocessing:Feature Extraction &
Rendering
Simulation
63 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
63
Parallel Framework
Parallel Vortex Extraction
0 200 400 600 800 1000
16
8
4
2
1
#Pro
zess
ors
Run Time [s]
922s
82s
[IMACS 2000, SC 2004, EGVE 2003, EGPGV 2006, SC 2006, EGPGV 2007, ParCo 2007, SEARIS 2008, CGF 28(6)]
A. Gerndt, M. Wolter, B. Hentschel, I. Assenmacher, I. Tedjo, S. Pick, A. Kelle‐Emden
64 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
64
Interactive Particle Tracing on the GPU
GPUCPU
Seed Point Specification
Cell Search Particle Seeding
Geometry Preparation
Rendering
SwapParticle Advection
GPUCPUSeed Point
Specification
Cell Search
Particle Seeding
Geometry Preparation Rendering
Particle Advection
M. Schirski
65 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
65
“The Virtual Windtunnel Revisited”
[IEEE VR 2005, SIGGRAPH 2005 Poster, C&G 29(1), VMV 2006, MMVR 2007, EGVE 2007]
• GPU-based Real-Time Particle Tracing• Works for structured as well as unstructured grids and for time-varying datasets• Advanced Billboard Rendering (Virtual Tubelets)
Marc Schirski et al.
66 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
66
Handling Large Data: Regions of Interest
67 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
67
Framework for Interactive FlowVis & More
Ultra High Performance Large Storage High Latency
Medium/High Performance Medium/Small Storage Low Latency/Real-Time
Large-Scale Data Processing(Low- & Mid Frequency tasks)
Interactive Operations(High Frequency, Navigation)
[IMACS 2000, SC 2004, EGVE 2003, EGPGV 2006, SC 2006, EGPGV 2007, ParCo 2007, SEARIS 2008, CGF 28(6)]
Marc Wolter et al.
68 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
68
VR-Systems
Acceleration Sensor
Optical Tracking
Depth Camera
Microphone
Camera(s)
Pressure Sensors
Mechanical Tracking
Loud Speaker
Displays
Motion Platform
Force Feedback
… … hearing
visual system
proprioception
haptic
Sensor Fusion
World SimulationKI / Behavior
Network &Collaboration
StreamsStreamsStreams
Data Base Rendering
Human
69 Prof. Dr. Torsten W. Kuhlen | Immersive Visualization | WS 2014/15 | Course on Virtual Reality – Name des Kapitels
69
Topics
• What is Virtual Reality?
• VR Displays and Systems
• Stereoscopic, Viewer-Centered Projections
• VR in Scientific Visualization