Virtual reality (VR) is an emerging and powerful tool to visualize and explore complex scientific data sets in an intuitive, interactive and user-friendly manner. In this study, we explore the usage of VR to create an immersive visualization of hydrological extreme events based on climate simulations. We aim to make use of the added values of VR to promote the communication of scientific results on potential natural hazards to the public.

The visualization data are taken from climate simulations within the ClimEx project, which is an international collaboration between research facilities, universities and public water agencies in Bavaria and Quélbec. The project investigates the effects of climate change on meteorological and hydrological extreme events and implications for water management in the two regions. Within this project, an ensemble of 50 transient runs of the regional climate model CRCM5 were run at approximately 11 km spatial resolution for two domains in Europe and North America from 1950 to 2100. As each of these runs is initialized with only slightly altered starting conditions, this ensemble can be interpreted as modelled natural variability. From this data set, we extracted precipitation data regarding one historical flooding event, the Pentecost flood in Southern Germany and Austria in May 1999, as well as precipitation data for two designated future intense rainfall events in the 2060s and 2080s for the same region. Data for these three extreme rainfall events were visualized in VR using a 3D representation of topography of the region of interest as the background. This VR representation was enhanced with satellite images (on top of the topography), points of interest (for easier navigation) and images of the historic Pentecost flood event (for emphazising the impact of the flood event).

We will present the necessary steps to create this immersive virtual reality 3D visualization from the raw scientific data and discuss several aspects of the visual design and the adopted user interface

Kolb, Daniel

Kranzlmüller, Dieter

Kurtz, Wolfgang

Ludwig, Ralf

Ramm, Alexander von

Weismüller, Jens

English

Open Access LMU

Using virtual reality to visualize extreme rainfall events derived from climate simulations

Universität München: Elektronischen Publikationen

Phone: +49 89 35831 - 8000
Fax: +49 89 35831 - 9700
Boltzmannstraße 1
85748 Garching near Munich
E-mail:  lrzpost@lrz.de
Internet: www.lrz.de
Introduction
Virtual Reality is a powerful tool for scienti c visualization and science 
communication. Utilizing all three spatial dimensions as well as intuitive interaction 
methods allows us to present large sets of data in immersive ways. 
We present a VR visualization of precipitation data pertaining to the hydrological 
area of Bavaria. 
Data originating from the ClimEx Project1:
  Climate change simulation for 1950-2100
  RCP 8.5 scenario using the Canadian Regional Climate Model (CRCM5)
  50-member ensemble run on the SuperMUC
  Numerous climatological and hydrological variables, e.g. temperature, 
pressure, soil humidity and rainfall
Our goal is a scienti c visualization that is:
  Able to display various events of 60 hours of accumulated rainfall each
  Immersive and engaging
  Easy to control and understand, especially for non-experts
  Open to exploration
  Able to render 90+ frames per second per eye on commercial hardware
Method
We use the feature-rich Unreal Engine 4 to design the 3D scene as well as the VR 
interaction. For this we create a 3D surface from the grid of data values. The z-value 
of the surface corresponds to the aggregated amount of rainfall since the beginning 
of each respective event.
Interaction design 
  Coloring along a discrete gradient to ease 
 visual comparability
  User-facing name plates for major cities
  Single controller as input device with
  a date and time indicator for the 
current time step
  Icons for the button assignment
  a legend for the color mapping
  Controls for  ight and steering of the  
 visualization
Virtual representation of the controller
3D Scene
Generation of raw 3D geometries
Digital elevation model Satellite images
Reduction and smoothing of 3D objects
Landscape
Scientific data
Discrete time steps
Segmentation and levels of detail
Results
We were able to present our VR visualization to a wide  eld of interested people 
in varied settings. The users included prospective secondary school graduates 
evaluating branches of study, climate scientists, non-climate scientists, politicians, 
elder citizens and other decision makers. While di erent groups focused on di erent 
aspects of the visualization, all were able to independently control and explore the 
VR application with minimal introduction and guidance. 
Three points of view of the historical rainfall event of 1999
Three points of view of the 2040-2070 event
Three points of view of the 2070-2100 event
Using virtual reality to visualize extreme rainfall events derived from climate simulations 
Daniel Kolb, Wolfgang Kurtz, Jens Weismüller, Alexander von Ramm, Dieter Kranzlmüller, Leibniz Supercomputing Centre, Garching near Munich, Germany
Ralf Ludwig, Ludwig-Maximilians-Universität, Munich, Germany
The use of a commercial game engine and a straightforward interaction design 
allowed us to expand the application to further teaching settings with limited e ort. 
Currently available exploration options:
  Small co-operating groups in a CAVE automatic virtual environment
  Lectures to larger groups using a 3D-capable powerwall
  Autonomous exploration with a head-mounted display (HMD)
Conclusion
We have developed a way to present data results from climate computations in 
an immersive and accessible manner. 
Challenges:
1. Boundaries imposed by hardware:
  Rendering time
  Memory usage
2. Technological barrier to exploring the virtual world:
  Powerful, yet concise controls
  Meaningful, yet unhindering displays
  Comprehensibility of the presentation
Solutions:
1. Optimization of the 3D meshes:
  Polygon count reduction
  Laplace Smoothing
  Level of detail system
2. Application of familiar design patterns and principles:
  Contour lines
  Established UI designs
  Flat interaction hierarchy
  Feedback on current status
  Visible input options
Acknowledgement
We would like to thank our colleagues, Elisabeth Mayer, Lea Weil and Kristian 
Weinand, for their support with the processing of 3D objects as well as their helpful 
feedback on design choices. We also gratefully acknowledge funding of the project 
ClimEx by the Bavarian State Ministry of the Environment and Consumer Protection.
References
1Leduc, Martin, et al. „ClimEx project: a 50-member ensemble of climate change 
projections at 12-km resolution over Europe and northeastern North America with 
the Canadian Regional Climate Model (CRCM5).“ Journal of Applied Meteorology and 
Climatology 2019.
Contact
Daniel Kolb
Boltzmannstraße 1
85748 Garching bei München
Phone: +49 89 35831-7891
E-Mail: daniel.kolb@lrz.de


Phone: +49 89 35831 - 8000Fax: +49 89 35831 - 9700Boltzmannstraße 185748 Garching near MunichE-mail:  lrzpost@lrz.deInternet: www.lrz.deIntroductionVirtual Reality is a powerful tool for scienti c visualization and science communication. Utilizing all three spatial dimensions as well as intuitive interaction methods allows us to present large sets of data in immersive ways. We present a VR visualization of precipitation data pertaining to the hydrological area of Bavaria. Data originating from the ClimEx Project1:  Climate change simulation for 1950-2100  RCP 8.5 scenario using the Canadian Regional Climate Model (CRCM5)  50-member ensemble run on the SuperMUC  Numerous climatological and hydrological variables, e.g. temperature, pressure, soil humidity and rainfallOur goal is a scienti c visualization that is:  Able to display various events of 60 hours of accumulated rainfall each  Immersive and engaging  Easy to control and understand, especially for non-experts  Open to exploration  Able to render 90+ frames per second per eye on commercial hardwareMethodWe use the feature-rich Unreal Engine 4 to design the 3D scene as well as the VR interaction. For this we create a 3D surface from the grid of data values. The z-value of the surface corresponds to the aggregated amount of rainfall since the beginning of each respective event.Interaction design   Coloring along a discrete gradient to ease  visual comparability  User-facing name plates for major cities  Single controller as input device with  a date and time indicator for the current time step  Icons for the button assignment  a legend for the color mapping  Controls for  ight and steering of the   visualizationVirtual representation of the controller3D SceneGeneration of raw 3D geometriesDigital elevation model Satellite imagesReduction and smoothing of 3D objectsLandscapeScientific dataDiscrete time stepsSegmentation and levels of detailResultsWe were able to present our VR visualization to a wide  eld of interested people in varied settings. The users included prospective secondary school graduates evaluating branches of study, climate scientists, non-climate scientists, politicians, elder citizens and other decision makers. While di erent groups focused on di erent aspects of the visualization, all were able to independently control and explore the VR application with minimal introduction and guidance. Three points of view of the historical rainfall event of 1999Three points of view of the 2040-2070 eventThree points of view of the 2070-2100 eventUsing virtual reality to visualize extreme rainfall events derived from climate simulations Daniel Kolb, Wolfgang Kurtz, Jens Weismüller, Alexander von Ramm, Dieter Kranzlmüller, Leibniz Supercomputing Centre, Garching near Munich, GermanyRalf Ludwig, Ludwig-Maximilians-Universität, Munich, GermanyThe use of a commercial game engine and a straightforward interaction design allowed us to expand the application to further teaching settings with limited e ort. Currently available exploration options:  Small co-operating groups in a CAVE automatic virtual environment  Lectures to larger groups using a 3D-capable powerwall  Autonomous exploration with a head-mounted display (HMD)ConclusionWe have developed a way to present data results from climate computations in an immersive and accessible manner. Challenges:1. Boundaries imposed by hardware:  Rendering time  Memory usage2. Technological barrier to exploring the virtual world:  Powerful, yet concise controls  Meaningful, yet unhindering displays  Comprehensibility of the presentationSolutions:1. Optimization of the 3D meshes:  Polygon count reduction  Laplace Smoothing  Level of detail system2. Application of familiar design patterns and principles:  Contour lines  Established UI designs  Flat interaction hierarchy  Feedback on current status  Visible input optionsAcknowledgementWe would like to thank our colleagues, Elisabeth Mayer, Lea Weil and Kristian Weinand, for their support with the processing of 3D objects as well as their helpful feedback on design choices. We also gratefully acknowledge funding of the project ClimEx by the Bavarian State Ministry of the Environment and Consumer Protection.References1Leduc, Martin, et al. „ClimEx project: a 50-member ensemble of climate change projections at 12-km resolution over Europe and northeastern North America with the Canadian Regional Climate Model (CRCM5).“ Journal of Applied Meteorology and Climatology 2019.ContactDaniel KolbBoltzmannstraße 185748 Garching bei MünchenPhone: +49 89 35831-7891E-Mail: daniel.kolb@lrz.de

https://epub.ub.uni-muenchen.de/71906/1/Using%20virtual%20reality%20to%20visualize%20extreme%20rainfall%20events%20derived%20from%20climate%20simulations.pdf

Using virtual reality to visualize extreme rainfall events derived from climate simulations

Abstract

Similar works

Full text

Available Versions

Open Access LMU

Universität München: Elektronischen Publikationen

Open Access LMU