scholarly journals Virtual Valcamonica: Collaborative Exploration of Prehistoric Petroglyphs and Their Surrounding Environment in Multi-User Virtual Reality

2018 ◽  
Vol 26 (3) ◽  
pp. 297-321 ◽  
Author(s):  
Alexander Kulik ◽  
André Kunert ◽  
Stephan Beck ◽  
Carl-Feofan Matthes ◽  
Andre Schollmeyer ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Visual Analysis ◽  
Rock Art ◽  
Aggregate Size ◽  
Point Clouds ◽  
Added Value ◽  
3D Analysis ◽  
Interaction Techniques ◽  
3D Interaction ◽  
3D Point Clouds

In this article, we present a novel, multi-user, virtual reality environment for the interactive, collaborative 3D analysis of large 3D scans and the technical advancements that were necessary to build it: a multi-view rendering system for large 3D point clouds, a suitable display infrastructure, and a suite of collaborative 3D interaction techniques. The cultural heritage site of Valcamonica in Italy with its large collection of prehistoric rock-art served as an exemplary use case for evaluation. The results show that our output-sensitive level-of-detail rendering system is capable of visualizing a 3D dataset with an aggregate size of more than 14 billion points at interactive frame rates. The system design in this exemplar application results from close exchange with a small group of potential users: archaeologists with expertise in rockart. The system allows them to explore the prehistoric art and its spatial context with highly realistic appearance. A set of dedicated interaction techniques was developed to facilitate collaborative visual analysis. A multi-display workspace supports the immediate comparison of geographically distributed artifacts. An expert review of the final demonstrator confirmed the potential for added value in rock-art research and the usability of our collaborative interaction techniques.

scholarly journals CLASSIFICATION AND INTEGRATION OF MASSIVE 3D POINTS CLOUDS IN A VIRTUAL REALITY (VR) ENVIRONMENT

2019 ◽  
Vol XLII-2/W17 ◽  
pp. 165-171 ◽  
Author(s):  
A. Kharroubi ◽  
R. Hajji ◽  
R. Billen ◽  
F. Poux
Keyword(s):  
Virtual Reality ◽  
Open Source ◽  
Point Cloud ◽  
Mixed Reality ◽  
Automatic Segmentation ◽  
Point Clouds ◽  
3D Point Clouds ◽  
3D Data ◽  
Segmentation Approach ◽  
And Performance

Abstract. With the increasing volume of 3D applications using immersive technologies such as virtual, augmented and mixed reality, it is very interesting to create better ways to integrate unstructured 3D data such as point clouds as a source of data. Indeed, this can lead to an efficient workflow from 3D capture to 3D immersive environment creation without the need to derive 3D model, and lengthy optimization pipelines. In this paper, the main focus is on the direct classification and integration of massive 3D point clouds in a virtual reality (VR) environment. The emphasis is put on leveraging open-source frameworks for an easy replication of the findings. First, we develop a semi-automatic segmentation approach to provide semantic descriptors (mainly classes) to groups of points. We then build an octree data structure leveraged through out-of-core algorithms to load in real time and continuously only the points that are in the VR user's field of view. Then, we provide an open-source solution using Unity with a user interface for VR point cloud interaction and visualisation. Finally, we provide a full semantic VR data integration enhanced through developed shaders for future spatio-semantic queries. We tested our approach on several datasets of which a point cloud composed of 2.3 billion points, representing the heritage site of the castle of Jehay (Belgium). The results underline the efficiency and performance of the solution for visualizing classifieds massive point clouds in virtual environments with more than 100 frame per second.

scholarly journals COMPARISON OF UAV-ENABLED PHOTOGRAMMETRY-BASED 3D POINT CLOUDS AND INTERPOLATED DSMs OF SLOPING TERRAIN FOR ROCKFALL HAZARD ANALYSIS

2016 ◽  
Vol XLII-2/W2 ◽  
pp. 71-77 ◽  
Author(s):  
J. Manousakis ◽  
D. Zekkos ◽  
F. Saroglou ◽  
M. Clark
Keyword(s):  
Feature Recognition ◽  
Hazard Analysis ◽  
Model Development ◽  
Back Analysis ◽  
Point Clouds ◽  
3D Analysis ◽  
Control Points ◽  
Image Block ◽  
Rockfall Hazard ◽  
3D Point Clouds

UAVs are expected to be particularly valuable to define topography for natural slopes that may be prone to geological hazards, such as landslides or rockfalls. UAV-enabled imagery and aerial mapping can lead to fast and accurate qualitative and quantitative results for photo documentation as well as basemap 3D analysis that can be used for geotechnical stability analyses. In this contribution, the case study of a rockfall near Ponti village that was triggered during the November 17th 2015 M<sub>w</sub> 6.5 earthquake in Lefkada, Greece is presented with a focus on feature recognition and 3D terrain model development for use in rockfall hazard analysis. A significant advantage of the UAV was the ability to identify from aerial views the rockfall trajectory along the terrain, the accuracy of which is crucial to subsequent geotechnical back-analysis. Fast static GPS control points were measured for optimizing internal and external camera parameters and model georeferencing. Emphasis is given on an assessment of the error associated with the basemap when fewer and poorly distributed ground control points are available. Results indicate that spatial distribution and image occurrences of control points throughout the mapped area and image block is essential in order to produce accurate geospatial data with minimum distortions.

scholarly journals VISUALIZING 3D CLIMATE DATA IN URBAN 3D MODELS

2020 ◽  
Vol XLIII-B4-2020 ◽  
pp. 781-789
Author(s):  
J. Gautier ◽  
S. Christophe ◽  
M. Brédif
Keyword(s):  
Visual Analysis ◽  
Urban Climate ◽  
Point Clouds ◽  
3D Models ◽  
Urban Morphology ◽  
Climate Data ◽  
Urban City ◽  
3D Point Clouds ◽  
Simulated Climate ◽  
City Model

Abstract. In order to understand and explain urban climate, the visual analysis of urban climate data and their relationships with the urban morphology is at stake. This involves partly to co-visualize 3D field climate data, obtained from simulation, with urban 3D models. We propose two ways to visualize and navigate into simulated climate data in urban 3D models, using series of horizontal 2D planes and 3D point clouds. We then explore different parameters regarding transparency, 3D semiologic rules, filtering and animation functions in order to improve the visual analysis of climate data 3D distribution. To achieve this, we apply our propositions to the co-visualization of air temperature data with a 3D urban city model.

scholarly journals 3DUI-EF: Towards a Framework for Easy Empirical Evaluation of 3D User Interfaces and Interaction Techniques

2010 ◽  
Vol 9 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Christophe Domingues ◽  
Samir Otmane ◽  
Malik Mallem
Keyword(s):  
Virtual Reality ◽  
User Interfaces ◽  
Empirical Evaluation ◽  
Interaction Techniques ◽  
3D Interaction ◽  
Interaction Technique ◽  
Data Mining Algorithms ◽  
Development Lifecycle ◽  
3D User Interface ◽  
3D User Interfaces

Designing usable and effective 3D User Interfaces and 3D Interaction Techniques is very challenging for Virtual Reality system developers and human factors specialists. Indeed, time consuming empirical evaluation is necessary to have an idea about the goodness of the 3D User Interface (3DUI) and the 3D Interaction Technique (3DIT) at the end of their development lifecycle. This may induce a huge loss of time if the result appears not to be satisfying in the end. Moreover, 3DUI evaluation is much more complex than 2D User Interfaces evaluation which is due to heterogeneous Virtual Reality (VR) devices and 3DIT. The aim of this work is to provide a framework allowing developers and experimenters to quickly evaluate 3DUIs and 3DITs during the design and the development lifecycle. The proposed framework is divided into two tools. The first one enables to create an evaluation protocol based on a knowledge database using two data mining algorithms, the "C4.5" to avoid from impossible combinations between devices and indicators and the "Spv Assoc Tree" to build a decision tree between indicators and factors. The second tool of the framework is an Evaluation Virtual Environment (EVE) to perform the evaluation according the protocol created with the first tool.

Manual Preliminary Coarse Alignment of 3D Point Clouds in Virtual Reality

2021 ◽  
pp. 424-432
Author(s):  
Xiaotian Zhang ◽  
Weiping He ◽  
Shuxia Wang
Keyword(s):  
Virtual Reality ◽  
Point Clouds ◽  
3D Point Clouds

Building-Scale Virtual Reality

2019 ◽  
Vol 10 (1) ◽  
pp. 1-21
Author(s):  
Katashi Nagao ◽  
Menglong Yang ◽  
Yusuke Miyakawa
Keyword(s):  
Virtual Reality ◽  
Real World ◽  
Point Cloud ◽  
Point Clouds ◽  
3D Point Cloud ◽  
Pose Tracking ◽  
3D Point Clouds ◽  
Localization And Mapping ◽  
Real World Applications ◽  
Using Data

A method is presented that extends the real world into all buildings. This building-scale virtual reality (VR) method differs from augmented reality (AR) in that it uses automatically generated 3D point cloud maps of building interiors. It treats an entire indoor area a pose tracking area by using data collected using an RGB-D camera mounted on a VR headset and using deep learning to build a model from the data. It modifies the VR space in accordance with its intended usage by using segmentation and replacement of the 3D point clouds. This is difficult to do with AR but is essential if VR is to be used for actual real-world applications, such as disaster simulation including simulation of fires and flooding in buildings. 3D pose tracking in the building-scale VR is more accurate than conventional RGB-D simultaneous localization and mapping.

scholarly journals Symmetry Analysis of Oriental Polygonal Pagodas Using 3D Point Clouds for Cultural Heritage

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1228
Author(s):  
Ting On Chan ◽  
Linyuan Xia ◽  
Yimin Chen ◽  
Wei Lang ◽  
Tingting Chen ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Unmanned Aerial Vehicle ◽  
Point Cloud ◽  
Geometric Model ◽  
Digital Camera ◽  
Point Clouds ◽  
Symmetry Analysis ◽  
3D Point Clouds ◽  
Transmission Towers ◽  
Aerial Vehicle

Ancient pagodas are usually parts of hot tourist spots in many oriental countries due to their unique historical backgrounds. They are usually polygonal structures comprised by multiple floors, which are separated by eaves. In this paper, we propose a new method to investigate both the rotational and reflectional symmetry of such polygonal pagodas through developing novel geometric models to fit to the 3D point clouds obtained from photogrammetric reconstruction. The geometric model consists of multiple polygonal pyramid/prism models but has a common central axis. The method was verified by four datasets collected by an unmanned aerial vehicle (UAV) and a hand-held digital camera. The results indicate that the models fit accurately to the pagodas’ point clouds. The symmetry was realized by rotating and reflecting the pagodas’ point clouds after a complete leveling of the point cloud was achieved using the estimated central axes. The results show that there are RMSEs of 5.04 cm and 5.20 cm deviated from the perfect (theoretical) rotational and reflectional symmetries, respectively. This concludes that the examined pagodas are highly symmetric, both rotationally and reflectionally. The concept presented in the paper not only work for polygonal pagodas, but it can also be readily transformed and implemented for other applications for other pagoda-like objects such as transmission towers.

scholarly journals Controlling Teleportation-Based Locomotion in Virtual Reality with Hand Gestures: A Comparative Evaluation of Two-Handed and One-Handed Techniques

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 715
Author(s):  
Alexander Schäfer ◽  
Gerd Reis ◽  
Didier Stricker
Keyword(s):  
Virtual Reality ◽  
Virtual Worlds ◽  
User Preferences ◽  
Interaction Techniques ◽  
Hand Gestures ◽  
Wide Range ◽  
Effectiveness And Efficiency ◽  
High Degree ◽  
Additional Hardware ◽  
Comprehensive Study

Virtual Reality (VR) technology offers users the possibility to immerse and freely navigate through virtual worlds. An important component for achieving a high degree of immersion in VR is locomotion. Often discussed in the literature, a natural and effective way of controlling locomotion is still a general problem which needs to be solved. Recently, VR headset manufacturers have been integrating more sensors, allowing hand or eye tracking without any additional required equipment. This enables a wide range of application scenarios with natural freehand interaction techniques where no additional hardware is required. This paper focuses on techniques to control teleportation-based locomotion with hand gestures, where users are able to move around in VR using their hands only. With the help of a comprehensive study involving 21 participants, four different techniques are evaluated. The effectiveness and efficiency as well as user preferences of the presented techniques are determined. Two two-handed and two one-handed techniques are evaluated, revealing that it is possible to move comfortable and effectively through virtual worlds with a single hand only.

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