Exploiting Position History for Efficient Remote Rendering in Networked Virtual Reality

1995 ◽  
Vol 4 (2) ◽  
pp. 169-193 ◽  
Author(s):  
Sandeep K. Singhal ◽  
David R. Cheriton
Keyword(s):  
Virtual Reality ◽  
Dead Reckoning ◽  
Frame Rate ◽  
Position Information ◽  
Network Bandwidth ◽  
Support Interaction ◽  
Remote Rendering ◽  
Higher Derivative ◽  
Derivative Information ◽  
Local Machine

Distributed virtual reality systems require accurate, efficient remote rendering of animated entities in the virtual environment. Position, velocity, and acceleration information about each player is maintained at the player's local machine, but remote hosts must display this information in real-time to support interaction between users across the network. Prior applications have transmitted position information at the local frame rate, or they have relied on dead-reckoning protocols using higher derivative information to extrapolate entity position between less frequent updates. These approaches require considerable network bandwidth and at times exhibit poor behavior. This paper describes a position history-based protocol whose update packets contain only position information. Remote hosts extrapolate from several position updates to track the location and orientation of entities between infrequent updates. Our evaluation suggests that the position history-based protocol provides a network-scalable solution for generating smooth, accurate rendering of remote entities.

Motion-Aware Adaptive Dead Reckoning Algorithm for Distributed Virtual Reality Systems

2012 ◽  
Author(s):  
Vasily Y. Kharitonov
Keyword(s):  
Virtual Reality ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Dead Reckoning ◽  
Object Motion ◽  
Data Consistency ◽  
Motion Pattern ◽  
Network Bandwidth ◽  
Account Information ◽  
Distributed Virtual Reality

Dead reckoning algorithms are employed in distributed virtual reality systems (DVR systems) for predicting objects states at any given moment of time that makes it possible to minimize bandwidth requirements while maintaining required data consistency. However, existing implementations often do not take into account information on the object motion dynamics and, in general, apply static prediction models. In this paper a novel motion-aware adaptive dead reckoning algorithm is introduced based on dynamical prediction model selection depending on the object motion pattern. The results show that considerable reduction in update messages can be achieved without sacrificing prediction accuracy. In addition, it becomes possible to dynamically adjust the size of update messages according to the motion pattern and, thus, provide more flexible use of network bandwidth.

Design of Continuous Indoor Navigation System Based on INS and Wifi

2013 ◽  
Vol 303-306 ◽  
pp. 2046-2049 ◽  
Author(s):  
Yi Hu ◽  
Lei Sheng ◽  
Shan Jun Zhang
Keyword(s):  
Navigation System ◽  
Smart Phone ◽  
Dead Reckoning ◽  
Indoor Positioning ◽  
Indoor Navigation ◽  
High Price ◽  
Position Information ◽  
Positioning Method ◽  
Indoor Navigation System ◽  
Navigation Service

The application of navigation, such as guidance of pedestrians, requires a certain accuracy of continuous outdoor and indoor positioning. In outdoor environments GPS system has proved to be effective. However in indoor it is challenging to control the accuracy within 2 to 3 meters. At present several approaches have been developed for indoor positioning, such as RFID. But they are mainly been implemented in professional areas, for general user such as tourists and visual incapable users it is difficult to take advantage of these technologies because of the high price of terminal and the navigation service covered area is extremely limited. In this paper, a new approach of indoor navigation method is proposed to solve the problems of traditional methods. It is based on INS and wifi positioning technology. As hardware, wifi receiver, smart phone built-in accelerometer and digital compass are selected and investigated. User’s indoor position is first estimated by dead reckoning method with INS navigation system and then be recalibrated by wifi position information. Several experiments performed in the test verified the effectiveness of this indoor continuous positioning method described in this paper.

scholarly journals A Novel Method of Adaptive Kalman Filter for Heading Estimation Based on an Autoregressive Model

2019 ◽  
Vol 9 (18) ◽  
pp. 3727
Author(s):  
Chai ◽  
Chen ◽  
Wang
Keyword(s):  
Kalman Filter ◽  
Autoregressive Model ◽  
Dead Reckoning ◽  
Position Estimation ◽  
Average Error ◽  
Adaptive Kalman Filter ◽  
Position Information ◽  
Variance Matrix ◽  
Heading Estimation ◽  
Pedestrian Dead Reckoning

With the popularity of smartphones and the development of microelectromechanical system (MEMS), the pedestrian dead reckoning (PDR) algorithm based on the built-in sensors of a smartphone has attracted much research. Heading estimation is the key to obtaining reliable position information. Hence, an adaptive Kalman filter (AKF) based on an autoregressive model (AR) is proposed to improve the accuracy of heading for pedestrian dead reckoning in a complex indoor environment. Our approach uses an autoregressive model to build a Kalman filter (KF), and the heading is calculated by the gyroscope, obtained by the magnetometer, and stored by previous estimates, then are fused to determine the measurement heading. An AKF based on the innovation sequence is used to adaptively adjust the state variance matrix to enhance the accuracy of the heading estimation. In order to suppress the drift of the gyroscope, the heading calculated by the AKF is used to correct the heading calculated by the outputs of the gyroscope if a quasi-static magnetic field is detected. Data were collected using two smartphones. These experiments showed that the average error of two-dimensional (2D) position estimation obtained by the proposed algorithm is reduced by 40.00% and 66.39%, and the root mean square (RMS) is improved by 43.87% and 66.79%, respectively, for these two smartphones.

scholarly journals Effective volume rendering on mobile and standalone VR headsets by means of a hybrid method

2020 ◽  
Vol 15 (2) ◽  
pp. 3-12
Author(s):  
Balázs Tukora
Keyword(s):  
Virtual Reality ◽  
Volume Rendering ◽  
Texture Mapping ◽  
Volume Visualization ◽  
Frame Rate ◽  
Hybrid Technique ◽  
Ray Casting ◽  
Volumetric Data ◽  
3D Texture ◽  
Rendering Techniques

Abstract:Numerous volume rendering techniques are available to display 3D datasets on desktop computers and virtual reality devices. Recently the spreading of mobile and standalone virtual reality headsets has brought the need for volume visualization on these platforms too. However, the volume rendering techniques that show good performance in desktop environment underachieve on these devices, due to the special hardware conditions and visualization requirements. To speed up the volumetric rendering to an accessible level a hybrid technique is introduced, a mix of the ray casting and 3D texture mapping methods. This technique increases 2-4 times the frame rate of displaying volumetric data on mobile and standalone virtual reality headsets as compared to the original methods. The new technique was created primarily to display medical images but it is not limited only to this type of volumetric data.

scholarly journals Impact Sound Generation for Audiovisual Interaction with Real-World Movable Objects in Building-Scale Virtual Reality

2021 ◽  
Vol 11 (16) ◽  
pp. 7546
Author(s):  
Katashi Nagao ◽  
Kaho Kumon ◽  
Kodai Hattori
Keyword(s):  
Virtual Reality ◽  
Real World ◽  
Large Scale ◽  
Virtual Space ◽  
Sound Generation ◽  
Generation System ◽  
Position Information ◽  
3D Data ◽  
The Impact ◽  
Audiovisual Interaction

In building-scale VR, where the entire interior of a large-scale building is a virtual space that users can walk around in, it is very important to handle movable objects that actually exist in the real world and not in the virtual space. We propose a mechanism to dynamically detect such objects (that are not embedded in the virtual space) in advance, and then generate a sound when one is hit with a virtual stick. Moreover, in a large indoor virtual environment, there may be multiple users at the same time, and their presence may be perceived by hearing, as well as by sight, e.g., by hearing sounds such as footsteps. We, therefore, use a GAN deep learning generation system to generate the impact sound from any object. First, in order to visually display a real-world object in virtual space, its 3D data is generated using an RGB-D camera and saved, along with its position information. At the same time, we take the image of the object and break it down into parts, estimate its material, generate the sound, and associate the sound with that part. When a VR user hits the object virtually (e.g., hits it with a virtual stick), a sound is generated. We demonstrate that users can judge the material from the sound, thus confirming the effectiveness of the proposed method.

scholarly journals Virtual Reality Application of the Fortress Al Zubarah in Qatar Including Performance Analysis of Real-Time Visualisation

2021 ◽  
Author(s):  
Thomas Kersten ◽  
Daniel Drenkhan ◽  
Simon Deggim
Keyword(s):  
Virtual Reality ◽  
Real Time ◽  
Virtual Worlds ◽  
3D Models ◽  
Frame Rate ◽  
Computer Hardware ◽  
Head Mounted Display ◽  
Digital World ◽  
Cad Models ◽  
Game Engines

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.

scholarly journals PDR Combined with Magnetic Fingerprint Algorithm for Indoor Positioning

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 24
Author(s):  
He Huang ◽  
Kaiyue Qiu ◽  
Wei Li ◽  
Dean Luo
Keyword(s):  
Relative Position ◽  
Dead Reckoning ◽  
Indoor Positioning ◽  
Fingerprint Matching ◽  
Localization Algorithm ◽  
Position Information ◽  
Matching Algorithm ◽  
Advantages And Disadvantages ◽  
Positioning Method ◽  
Particle Filter Algorithm

Geomagnetism has become a popular technology for indoor positioning, and its accuracy mainly depends on the accuracy of the geomagnetic matching algorithm. Pedestrian dead reckoning technology can calculate the relative position of pedestrians based on sensor information, but only obtain relative position information. According to the advantages and disadvantages of these two techniques, a high-precision GPDR indoor positioning method is proposed, and the improved particle filter algorithm is used to solve the problem of geomagnetic fingerprint fuzzy solution. Finally, a simulation experiment was conducted. The experimental results show that the accuracy of the proposed fusion localization algorithm is 42% higher than that of the PDR algorithm. Compared with a single geomagnetic fingerprint matching algorithm, the positioning accuracy is improved by 57%.

AN IMPROVED VIEW FRUSTUM CULLING METHOD USING OCTREES FOR 3D REAL-TIME RENDERING

2013 ◽  
Vol 13 (03) ◽  
pp. 1350009
Author(s):  
PAULO ROBERTO DE CARVALHO ◽  
MAIKON CISMOSKI DOS SANTOS ◽  
WILLIAM ROBSON SCHWARTZ ◽  
HELIO PEDRINI
Keyword(s):  
Virtual Reality ◽  
Virtual Environments ◽  
Real Time ◽  
Computer Games ◽  
Frame Rate ◽  
Visual Simulation ◽  
3D Graphics ◽  
Spatial Partitioning ◽  
Terrain Visualization ◽  
View Frustum Culling

The generation of real-time 3D graphics scenes normally demands high computational requirements. Several applications can benefit from efficient algorithms for rendering complex virtual environments, such as computer games, terrain visualization, virtual reality and visual simulation. This paper describes an improved view frustum culling method using spatial partitioning based on octrees for 3D real-time rendering. The proposed method is compared against two other approaches. Experiments using four different scenes are conducted to evaluate the performance of each tested method. Results demonstrate that the proposed method presents superior frame rate for all scenes.

scholarly journals Cooperation Between Dead Reckoning (Path Integration) and External Position Cues

1998 ◽  
Vol 51 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Ariane S. Etienne ◽  
Roland Maurer ◽  
Joëlle Berlie ◽  
Valérie Derivaz ◽  
Joséphine Georgakopoulos ◽  
...  
Keyword(s):  
Path Integration ◽  
Dead Reckoning ◽  
Linear Acceleration ◽  
Inertial Forces ◽  
Current Position ◽  
Position Information ◽  
Precise Position ◽  
Somatosensory Feedback ◽  
External Position ◽  
Internal Information

Dead reckoning (also called path integration) is the process by which a navigating organism derives its current position relative to an Earthbound reference point from its own locomotion. Dead reckoning requires the continuous estimation of changes in direction and location through self-generated signals and the computation of position on the basis of these signals.(i) Hymenopterous insects measure rotations and translations mainly with the help of optical references such as the Sun and translational visual flow. By contrast, mammals are able to estimate their position on the basis of purely ‘internal’ information; that is, signals generated in the vestibular system by inertial forces, somatosensory feedback, and efference copies (copies of central commands that control the performance of rotations and translations). Obviously, the assessment of the angular and linear components of locomotion is much more precise if it is assisted by external references than if this is not the case.(ii) Only man-made dead reckoning systems yield precise position information through the twofold integration over time of inertial signals deriving from angular and linear acceleration. On the biological level, all species tested so far seem to rely on a simplified form of path ‘integration’: in certain test situations, arthropods and mammals (including humans) commit similar systematic errors. This suggests that species from unrelated taxa update position according to a similar algorithm.

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
Keyword(s):  
Virtual Reality ◽  
Large Scale ◽  
3D Visualization ◽  
Technological Development ◽  
3D Models ◽  
Frame Rate ◽  
The Arctic ◽  
Terrain Analysis ◽  
Bathymetric Data ◽  
Digital Elevation

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.

Sign in / Sign up

Export Citation Format

Share Document