scholarly journals Virtual Reality in Cartography: Immersive 3D Visualization of the Arctic Clyde Inlet (Canada) Using Digital Elevation Models and Bathymetric Data

2019 ◽  
Vol 3 (1) ◽  
pp. 9 ◽  
Author(s):  
Mona Lütjens ◽  
Thomas Kersten ◽  
Boris Dorschel ◽  
Felix Tschirschwitz

Due to rapid technological development, virtual reality (VR) is becoming an accessible and important tool for many applications in science, industry, and economy. Being immersed in a 3D environment offers numerous advantages especially for the presentation of geographical data that is usually depicted in 2D maps or pseudo 3D models on the monitor screen. This study investigated advantages, limitations, and possible applications for immersive and intuitive 3D terrain visualizations in VR. Additionally, in view of ever-increasing data volumes, this study developed a workflow to present large scale terrain datasets in VR for current mid-end computers. The developed immersive VR application depicts the Arctic fjord Clyde Inlet in its 160 km × 80 km dimensions at 5 m spatial resolution. Techniques, such as level of detail algorithms, tiling, and level streaming, were applied to run the more than one gigabyte large dataset at an acceptable frame rate. The immersive VR application offered the possibility to explore the terrain with or without water surface by various modes of locomotion. Terrain textures could also be altered and measurements conducted to receive necessary information for further terrain analysis. The potential of VR was assessed in a user survey of persons from six different professions.

2011 ◽  
Vol 6 ◽  
pp. 267-274
Author(s):  
Stanislav Popelka ◽  
Alžběta Brychtová

Olomouc, nowadays a city with 100,000 inhabitants, has always been considered as one of the most prominent Czech cities. It is a social and economical centre, which history started just about the 11th century. The present appearance of the city has its roots in the 18th century, when the city was almost razed to the ground after the Thirty years’ war and a great fire in 1709. After that, the city was rebuilt to a baroque military fortress against Prussia army. At the beginning of the 20th century the majority of the fortress was demolished. Character of the town is dominated by the large number of churches, burgher’s houses and other architecturally significant buildings, like a Holy Trinity Column, a UNESCO World Heritage Site. Aim of this project was to state the most suitable methods of visualization of spatial-temporal change in historical build-up area from the tourist’s point of view, and to design and evaluate possibilities of spatial data acquisition. There are many methods of 2D and 3D visualization which are suitable for depiction of historical and contemporary situation. In the article four approaches are discussed comparison of historical and recent pictures or photos, overlaying historical maps over the orthophoto, enhanced visualization of historical map in large scale using the third dimension and photorealistic 3D models of the same area in different ages. All mentioned methods were geolocalizated using the Google Earth environment and multimedia features were added to enhance the impression of perception. Possibilities of visualization, which were outlined above, were realized on a case study of the Olomouc city. As a source of historical data were used rapport plans of the bastion fortress from the 17th century. The accuracy of historical maps was confirmed by cartometric methods with use of the MapAnalyst software. Registration of the spatial-temporal changes information has a great potential in urban planning or realization of reconstruction and particularly in the propagation of the region and increasing the knowledge of citizens about the history of Olomouc.


2021 ◽  
Vol 10 (10) ◽  
pp. 666
Author(s):  
Lei Zhang ◽  
Ping Wang ◽  
Chengyi Huang ◽  
Bo Ai ◽  
Wenjun Feng

Terrain rendering is an important issue in Geographic Information Systems and other fields. During large-scale, real-time terrain rendering, complex terrain structure and an increasing amount of data decrease the smoothness of terrain rendering. Existing rendering methods rarely use the features of terrain to optimize terrain rendering. This paper presents a method to increase rendering performance through precomputing roughness and self-occlusion information making use of GIS-based Digital Terrain Analysis. Our method is based on GPU tessellation. We use quadtrees to manage patches and take surface roughness in Digital Terrain Analysis as a factor of Levels of Detail (LOD) selection. Before rendering, we first regularly partition the terrain scene into view cells. Then, for each cell, we calculate its potential visible patch set (PVPS) using a visibility analysis algorithm. After that, A PVPS Image Pyramid is built, and each LOD level has its corresponding PVPS. The PVPS Image Pyramid is stored on a disk and is read into RAM before rendering. Based on the PVPS Image Pyramid and the viewpoint’s position, invisible terrain areas that are not culled through view frustum culling can be dynamically culled. We use Digital Elevation Model (DEM) elevation data of a square area in Henan Province to verify the effectiveness of this method. The experiments show that this method can increase the frame rate compared with other methods, especially for lower camera flight heights.


2019 ◽  
Vol 7 (1) ◽  
pp. 55-70
Author(s):  
Moh. Zikky ◽  
M. Jainal Arifin ◽  
Kholid Fathoni ◽  
Agus Zainal Arifin

High-Performance Computer (HPC) is computer systems that are built to be able to solve computational loads. HPC can provide a high-performance technology and short the computing processes timing. This technology was often used in large-scale industries and several activities that require high-level computing, such as rendering virtual reality technology. In this research, we provide Tawaf’s Virtual Reality with 1000 of Pilgrims and realistic surroundings of Masjidil-Haram as the interactive and immersive simulation technology by imitating them with 3D models. Thus, the main purpose of this study is to calculate and to understand the processing time of its Virtual Reality with the implementation of tawaf activities using various platforms; such as computer and Android smartphone. The results showed that the outer-line or outer rotation of Kaa’bah mostly consumes minimum times although he must pass the longer distance than the closer one.  It happened because the agent with the closer area to Kaabah is facing the crowded peoples. It means an obstacle has the more impact than the distances in this case.


Neurosurgery ◽  
2019 ◽  
Vol 85 (2) ◽  
pp. E343-E349 ◽  
Author(s):  
David Bairamian ◽  
Shinuo Liu ◽  
Behzad Eftekhar

Abstract BACKGROUND Three-dimensional (3D) visualization of the neurovascular structures has helped preoperative surgical planning. 3D printed models and virtual reality (VR) devices are 2 options to improve 3D stereovision and stereoscopic depth perception of cerebrovascular anatomy for aneurysm surgery. OBJECTIVE To investigate and compare the practicality and potential of 3D printed and VR models in a neurosurgical education context. METHODS The VR angiogram was introduced through the development and testing of a VR smartphone app. Ten neurosurgical trainees from Australia and New Zealand participated in a 2-part interactive exercise using 3 3D printed and VR angiogram models followed by a questionnaire about their experience. In a separate exercise to investigate the learning curve effect on VR angiogram application, a qualified neurosurgeon was subjected to 15 exercises involving manipulating VR angiograms models. RESULTS VR angiogram outperformed 3D printed model in terms of resolution. It had statistically significant advantage in ability to zoom, resolution, ease of manipulation, model durability, and educational potential. VR angiogram had a higher questionnaire total score than 3D models. The 3D printed models had a statistically significant advantage in depth perception and ease of manipulation. The results were independent of trainee year level, sequence of the tests, or anatomy. CONCLUSION In selected cases with challenging cerebrovascular anatomy where stereoscopic depth perception is helpful, VR angiogram should be considered as a viable alternative to the 3D printed models for neurosurgical training and preoperative planning. An immersive virtual environment offers excellent resolution and ability to zoom, potentiating it as an untapped educational tool.


Author(s):  
A. El Saer ◽  
C. Stentoumis ◽  
I. Kalisperakis ◽  
P. Nomikou

Abstract. In this work, we present a methodology for precise 3D modelling and multi-source geospatial data blending for the purposes of Virtual Reality immersive and interactive experiences. We evaluate it on the volcanic island of Santorini due to its formidable geological terrain and the interest it poses for scientific and touristic purposes. The methodology developed here consists of three main steps. Initially, bathymetric and SRTM data are scaled down to match the smallest resolution of our dataset (LIDAR). Afterwards, the resulted elevations are combined based on the slope of the relief, while considering a buffer area to enforce a smoother terrain. As a final step, the orthophotos are combined with the estimated Digital Terrain Model, via applying a nearest neighbour matching schema leading to the final terrain background. In addition to this, both onshore and offshore points-of-interest were modelled via image-based 3D reconstruction and added to the virtual scene. The overall geospatial data that need to be visualized in applications demanding photo-textured hyper-realistic models pose a significant challenge. The 3D models are treated via a mesh optimization workflow, suitable for efficient and fast visualization in virtual reality engines, through mesh simplification, physically based rendering texture maps baking, and level-of-details.


Author(s):  
Thomas Kersten ◽  
Daniel Drenkhan ◽  
Simon Deggim

AbstractTechnological advancements in the area of Virtual Reality (VR) in the past years have the potential to fundamentally impact our everyday lives. VR makes it possible to explore a digital world with a Head-Mounted Display (HMD) in an immersive, embodied way. In combination with current tools for 3D documentation, modelling and software for creating interactive virtual worlds, VR has the means to play an important role in the conservation and visualisation of cultural heritage (CH) for museums, educational institutions and other cultural areas. Corresponding game engines offer tools for interactive 3D visualisation of CH objects, which makes a new form of knowledge transfer possible with the direct participation of users in the virtual world. However, to ensure smooth and optimal real-time visualisation of the data in the HMD, VR applications should run at 90 frames per second. This frame rate is dependent on several criteria including the amount of data or number of dynamic objects. In this contribution, the performance of a VR application has been investigated using different digital 3D models of the fortress Al Zubarah in Qatar with various resolutions. We demonstrate the influence on real-time performance by the amount of data and the hardware equipment and that developers of VR applications should find a compromise between the amount of data and the available computer hardware, to guarantee a smooth real-time visualisation with approx. 90 fps (frames per second). Therefore, CAD models offer a better performance for real-time VR visualisation than meshed models due to the significant reduced data volume.


2020 ◽  
pp. 90-105
Author(s):  
V.I. Bogoyavlensky ◽  
◽  
I.V. Bogoyavlensky ◽  
T.N. Kargina ◽  
R.A. Nikonov ◽  
...  

In the course of the three years work in the Arctic with ArcticDEM digital elevation models (DEM), the researchers have obtained fundamentally new results on the natural catastrophic transformations of the landscapes of the Yamal Peninsula in the process of powerful gas blowouts and explosions. They have proved the possibility of detecting gas-explosive objects and processes during regional 4D monitoring based on DEM processing, and in the course of the retrospective 4D monitoring, have identified a number of potential gas blowout objects. The authors have identified disadvantages and proved the need for further improvement of the ArcticDEM data. They have built 3D-models of the areas of catastrophic induced gas blowouts during the drilling of exploration wells in the Arctic, including the Kumzhinskoye field. Using an unmanned aerial vehicle (drone DJI Mavic Pro), the researchers carried out aerial photography and built 3D models of a number of gas blowout craters. For the first time in Yamal, they performed an underground aerial photography of the gas blowout crater space C17, indicating the existence of a gas-sat


Author(s):  
Qiusheng Wu ◽  
Charles R. Lane ◽  
Lei Wang ◽  
Melanie K. Vanderhoof ◽  
Jay R. Christensen ◽  
...  

In terrain analysis and hydrological modeling, surface depressions (or sinks) in a digital elevation model (DEM) are commonly treated as artifacts and thus filled and removed to create a depressionless DEM. Various algorithms have been developed to identify and fill depressions in DEMs during the past decades. However, few studies have attempted to delineate and quantify the nested hierarchy of actual depressions, which can provide crucial information for characterizing surface hydrologic connectivity and simulating the fill-merge-spill hydrological process. In this paper, we present an innovative and efficient algorithm for delineating and quantifying nested depressions in DEMs using the level-set method based on graph theory. The proposed level-set method emulates water level decreasing from the spill point along the depression boundary to the lowest point at the bottom of a depression. By tracing the dynamic topological changes (i.e., depression splitting/merging) within a compound depression, the level-set method can construct topological graphs and derive geometric properties of the nested depressions. The experimental results of two fine-resolution LiDAR-derived DEMs show that the raster-based level-set algorithm is much more efficient (~150 times faster) than the vector-based contour tree method. The proposed level-set algorithm has great potential for being applied to large-scale ecohydrological analysis and watershed modeling.


2020 ◽  
Author(s):  
Sara Rolfe ◽  
Steve Pieper ◽  
Arthur Porto ◽  
Kelly Diamond ◽  
Julie Winchester ◽  
...  

ABSTRACTLarge scale digitization projects such as #ScanAllFishes and oVert are generating high-resolution microCT scans of vertebrates by the thousands. Data from these projects are shared with the community using aggregate 3D specimen repositories like MorphoSource through various open licenses. MorphoSource currently hosts tens of thousands of 3D scans of eukaryotes. Along with the data from similarly scoped projects such as 10kPhenomes, DigiMorph and many others, soon hundreds of thousands of specimens that represent biodiversity of extinct and extant organisms will be conveniently available to researchers. We anticipate an explosion of quantitative research in organismal biology with the convergence of available data and the methodologies to analyze them.Though the data are available, the road from a series of images to analysis is fraught with challenges for most biologists. It involves tedious tasks of data format conversions, preserving spatial scale of the data accurately, 3D visualization and segmentations, acquiring measurements and annotations. When scientists use commercial software with proprietary formats, a roadblock for data exchange, collaboration, and reproducibility is erected that hurts the efforts of the scientific community to broaden participation in research. Another relevant concern is that ultimate derivative data from individual research projects (e.g., 3D models of segmentation) are shared in formats that do not preserve the correct spatial scale of the data.In this paper, we present our effort to tackle challenges biologists face when conducting 3D specimen-based research. We developed SlicerMorph as an extension of 3D Slicer, a biomedical visualization and analysis ecosystem with extensive visualization and segmentation capabilities built on proven python-scriptable open-source libraries such as Visualization Toolkit and Insight Toolkit. In addition to the core functionalities of Slicer, SlicerMorph provides users with modules to conveniently retrieve open-access 3D models or import users own 3D volumes, to annotate 3D curve and patch-based landmarks, generate canonical templates, conduct geometric morphometric analyses of 3D organismal form using both landmark-driven and landmark-free approaches, and create 3D animations from their results. We highlight how these individual modules can be tied together to establish complete workflow(s) from image sequence to morphospace. Our software development efforts were supplemented with short courses and workshops that cover the fundamentals of 3D imaging and morphometric analyses as it applies to study of organismal form and shape in evolutionary biology, and extensive links to the existing tutorials are provided as supplemental material.Our goal is to establish a community of organismal biologists centered around Slicer and SlicerMorph to facilitate easy exchange of data and results and collaborations using 3D specimens. Our proposition to our colleagues is that using a common open platform supported by a large user and developer community ensures the longevity and sustainability of the tools beyond the initial development effort.


2018 ◽  
Vol 12 (3) ◽  
pp. 166-173
Author(s):  
Robert Župan ◽  
Stanislav Frangeš

The problem of modelling, especially of large-scale virtual urban environments such as city areas is today very challenging for cartographers. Cities are difficult to model in detail because of their often complex geometries. This paper describes the applied and tested new procedures for the development of a test three-dimensional urban area model using the Esri CityEngine software, which is based on procedural modelling. This process involves three steps. The first step is to collect the available data, as well as the Digital Model Relief data. The second step is to create a Computer Generated Architecture (CGA) file that contains a set of rules used by the software for an automatic generation of the model. The third step is to create and visualize 3D models in the CityEngine software because it can be programmed, for example, according to the rules of cartographic visualization. The Level of Detail (LOD) 2 was reconstructed. Several potential uses of such 3D visualization are also described.


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