International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY Paper Abstracts Conference Chairs Haşmet Gürçay Hacettepe University, Turkey Veysi İşler Middle East Technical University, Turkey Program Chair Murat Hacıömeroğlu Gazi University, Turkey Edited by Hacer İlhan Hacettepe University, Turkey Zümra Kavafoğlu Hacettepe University, Turkey HACETTEPE UNIVERSITY MIDDLE EAST TECHNICAL UNIVERSITY EURASIA GRAPHICS 2014
Transcript
International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
Paper Abstracts
Conference Chairs
Haşmet Gürçay Hacettepe University, Turkey
Veysi İşler Middle East Technical University, Turkey
Cumhur Yiğit ÖZCAN İlyas ÇİÇEKLİ Hacer İLHAN Hayri SEVER Öner BARUT
Zümra KAVAFOĞLU
International Program Committee Members
Alessandro ARTUSI Andreas WEBER
Aykut ERDEM Bernhard EBERHARDT
Bülent ÖZGÜÇ Çağatay BAŞDOĞAN
Çağatay TÜRKAY Ergun AKLEMAN
Erkut ERDEM Francesco BANTERLE
Gazihan ALANKUŞ Güven ÇATAK
Hacer Yalım KELEŞ Haşmet GÜRÇAY
Jan BENDER
Kresimir MATKOVIC Metin T. SEZGİN Murat HACIÖMEROĞLU Mustafa KASAP Nazli İkizler CİNBİŞ Selim BALCISOY Serdar ARITAN Stephen LAYCOCK Tolga ÇAPIN Uğur GÜDÜKBAY Umut DURAK Veysi İŞLER Xiaogang JIN Xiaosong YANG Zerrin YUMAK
1. Werner Purgathofer Accurate Fast Simulation of Light
2. Çağatay Türkay Interactive Visual Data Analysis in the Times of Big Data
PAPER SESSIONS
Session 1 (Chair: Bernd Eberhardt)
1. Özkan Anıl Töral, Serkan Ergun, Aydın Öztürk Real-Time Distant Light Filtering using Gaussian Mixture Model
2. Sermet Önel, Murat Kurt, Aydın Öztürk An Efficient Plugin for Representing Heterogeneous Translucent Materials
3. Arturo García, Omar Alvizo, Ulises Olivares, Félix Ramos Fast Data Parallel Radix Sort Implementation in DirectX 11 Compute Shader to Accelerate Ray Tracing Algorithms
Session 2 (Chair: Tolga Çapın)
4. Gökçe Yıldırım Kalkan, Veysi İşler Bottlenecks in Distributed Real-Time Visualization of Huge Data on Heterogeneous Systems
5. Erdem Kaya, M. Tolga Eren, Candemir Doger, Selim Balcisoy Do 3D Visualizations Fail? An Empirical Discussion on 2D and 3D Representations of the Spatio-temporal Data
6. Shengzhou Luo, John Dingliana Transfer Function Refinement for Exploring Volume Data
7. Emre Onal, Veysi Işler Cloth Tearing Simulation
8. Zümra Kavafoğlu, Hacer İlhan, Ersan Kavafoğlu, Haşmet Gürçay, Tolga Çapın Simple Vertical Human Climbing Control with End Effector State Machines
9. Aytek Aman, Ateş Akaydın, Uğur Güdükbay
Interacting with Boids in an Incompressible Fluid Environment
10. Oner Barut, Murat Hacıomeroglu, Cumhur Y. Ozcan, Hayri Sever A Dynamic Exit Choice Method for Real-Time Indoor Evacuation Scenarios
Session 4 (Chair: Hayri Sever)
11. Lal Gamze Bozgeyikli, Evren Can Bozgeyikli, Andrew Raij Keep Brushing! Developing Healthy Oral Hygiene Habits in Young Children with an Interactive Toothbrush
12. Numan Ali, Sehat Ullah, Aftab Alam, Jamal Rafique 3D Interactive Virtual Chemistry Laboratory for Simulation of High School Experiments
13. Gazihan Alankuş, Alp Arslan Eren Enhancing Gamepad FPS Controls with Tilt-Driven Sensitivity Adjustment
KEYNOTE SPEECHES
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Accurate Fast Simulation of Light
Werner Purgathofer
Vienna University of Technology
Abstract
Light distribution in a scene is a very complex issue if it shall be close to realism. For a lamp producing and light planning company such as Zumtobel it is of great value to be able to design installations interactively, providing immediate feedback to the costumers about the final result. Many aspects such as reflections and indirect lighting make this task difficult. This talk will give some ideas how a project at the research center VRVis approaches this topic, and which algorithms are useful for this. Where can we simplify without visible loss? How can we use the GPU to speed up the calculations? Why are virtual lights an efficient concept? Some example images provide evidence.
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Biography
Werner Purgathofer is a full professor of computer science and head of the Institute of Computer Graphics and Algorithms at the Technische Universitaet Wien (Vienna University of Technology), responsible for research and education in computer graphics. He has been working in this field since 1980 when he started his academic life as a research assistant, during which he received a Ph.D. in 1984 from TU Vienna. In 1981 and 1986 he received "best paper awards" at the Eurographics annual conferences. He has written a German
language textbook on computer graphics and coedited several other books. Purgathofer has organised the very successful 1991 and 2006 Eurographics annual conferences in Vienna. His current activities concentrate on rendering algorithms, color, and visualization. He is the president and scientific director of the VRVis research center for virtual reality and visualisation in Vienna (www.vrvis.at), which he founded in 2000. In 2001 he became vice-chair of the Commission for Scientific Visualisation of the Austrian Academy of Sciences. Purgathofer has been a member of Eurographics since 1981 and is also a member of the European Academy of Sciences, ACM, IEEE Computer Society, CGS, GI and several Austrian associations. Serving in the Executive Committee of Eurographics from 1988 until 2006, he was Publications Board Chairman from 1993 to 2000, and he became a fellow of the association in 1997. Together with Werner Hansmann, Francois Sillion and Dieter Fellner he is currently co-editor of the Eurographics Proceedings Series.In 2006 he received the Distinguished Career Award from Eurographics and in 2010 he received a Doctor honoris causa from the Technical University of Iasi. Since 2010 he is vice-chair of the Eurographics Association and chair of its Conference Steering Committee.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Interactive Visual Data Analysis in the Times of Big Data
Çağatay Türkay
City University
Abstract
We are now in an era where we are immersed in vast amounts of information as a society. Scientists and businesses have to work with data sets that are getting not only larger but also richer with respect to the types of information they contain. Although this richness is a big opportunity to build valuable insight, it still remains a big challenge how to best harness the information from the data. Automated computational approaches and visual methods have been widely used by analysts to accomplish this task. However when these methods are used alone on complex datasets, their effectivity is limited due to several factors, such as reliability or interpretability. A vision to overcome these challenges is integrating the best of automated computations and capabilities of the human. This has been a highly praised goal in visualization research and parallels the emergence of interactive data analysis (a.k.a visual analytics) as a field on its own. The talk will introduce how basic visual analysis methods operate and how such integrations are accomplished at different levels -- from static visualizations of computation results to giving user the interactive control on the inner workings of an algorithm. The talk will then move on to introducing "seamless" integrations where "task-oriented" computation results become natural elements of the interactive process and follow up with a discussion of opportunities and open issues with such approaches.
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Biography
Cagatay Turkay is a Lecturer in Applied Data Science at giCentre in the Computer Science Department at City University London. He has a PhD in visualization (University of Bergen, 2013), and MSc. (Sabanci Uni., Istanbul, 2010), and BSc. (METU, Ankara, 2009) in Computer Science and served as a visiting research fellow at Harvard University in 2013. His research mainly focuses on designing visualisations, interactions and processes to enable the tight integration of interactive visualizations, data analysis
techniques with exploratory capabilities of analysts. He works with experts in various domains from biomedicine, transport, retail, to security. He is the co-author of over 20 scientific publications, most of which are published in the most respected journals of the field, IEEE TVCG, IEEE CG&A, and CGF. He is a PC member for HCI-KDD expert board, EurasiaGraphics and MIUA conferences. He also serves as an active reviewer for IEEE VIS, EuroVis, IEEE TVCG, IEEE TBCC, CGI and several other journals and conferences. He is currently the local work-package leader for the VALCRI (EU FP7) and an investigator for the FareVis (TSB) projects.
PAPERS
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 1
Real-Time Distant Light Filtering using Gaussian Mixture Model
Özkan Anıl Töral1, Serkan Ergun2, Aydın Öztürk3
1Yaşar University, 2Ege University, 3İzmir University
Abstract
We propose a novel real-time rendering technique using Gaussian Mixture Models (GMMs) for environment lighting. We represent isotropic and anisotropic Bidirectional Reflectance Distribution Functions (BRDFs) using sum of Spherical Gaussians (SGs) fitted by Expectation-Maximization (EM) algorithm, which provide an accurate approximation with acceptable number of lobes. To suppress the approximation errors, we use Graphics Processing Unit (GPU) generated MIP-maps for filtering environment maps that does not require a pre-computation. MIP-mapped lookup is performed with the size of SG lobes to make filtering efficient. Based on empirical results, it is shown that both isotropic and anisotropic reflectances can be handled in real-time using our technique.
International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 2
An Efficient Plugin for Representing Heterogeneous Translucent Materials
Sermet Önel1, Murat Kurt2, Aydın Öztürk3
1Yaşar University, 2Ege University, 3İzmir University
Abstract
This paper presents a plugin that adds an efficient representation of heterogeneous translucent materials to the Blender 3D modeling tool. Algorithm of the plugin is based on Singular Value Decomposition (SVD) method and Mitsuba renderer is the default rendering software used by the proposed plugin. We validate the efficiency of the proposed plugin by using a set of measured heterogeneous subsurface scattering data sets.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 3
Fast Data Parallel Radix Sort Implementation in DirectX 11 Compute Shader to Accelerate Ray Tracing Algorithms
1Visual and Parallel computing group, Intel Coorporation,
2University of Guadalajara
3Center for Research and Advanced Studies of the National Polytechnic Institute
Abstract
In this paper we present a fast data parallel implementation of the radix sort on the DirectCompute software development kit (SDK). We also discuss in detail the various optimization strategies that were used to increase the performance of our radix sort, and we show how these strategies can be generalized for any video card that supports the DirectCompute model. The insights that we share in this paper should be of use to any General-Purpose Graphics Processing Unit (GPGPU) programmer regardless of the video card being used. Finally, we discuss how radix sort can be used to accelerate ray tracing and we present some results in this area as well.
Keywords: Data Parallel Radix Sort, Directx 11 Compute Shader, Ray Tracing.
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Paper 4
Bottlenecks in Distributed Real-Time Visualization of Huge Data on Heterogeneous Systems
Gökçe Yıldırım Kalkan1, Veysi İşler2
1Simsoft Bilg. Tekn. Ltd. Şti, 2Middle East Technical University
Abstract
In computer graphics, generating high-quality images at high frame rates for rendering complex scenes from huge data is a challenging task. A practical solution to tackling this problem is distributing the rendering load among heterogeneous computers or graphical processing units. In this article, we investigate the bottlenecks in a single processing unit or the connection between the several processing units that need to be overcome in such approaches. We provide simulation results for these bottlenecks and outline guidelines that can be useful for other researchers working on distributed real-time visualization of huge data.
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Paper 5
Do 3D Visualizations Fail? An Empirical Discussion on 2D and 3D Representations of the Spatio-temporal Data
Erdem Kaya, M. Tolga Eren, Candemir Doger, Selim Balcisoy
Sabanci University
Abstract
Having particular aspects diverging from otherkinds of data, spatio-temporal data may require conventional visualization techniques and tools to be modified and tailored for analysis purposes. However, there could be a number of pitfalls for the design of such analysis tools that completely relies on the well-known techniques with well-known limitations possibly due to the intrinsic characteristics of the data at hand. In this paper, we present an experimental study to empirically testify whether advantages and limitations of 2D and 3D representations are valid for the spatio-temporal data visualization. To form the basis for our experimental design, we interviewed domain experts from a location-based services company and identified different cases of spatio-temporal data analysis. Furthermore, we implemented two simple representations, namely density map and density cube, and conducted a laboratory experiment to compare aforementioned techniques from time and correctness perspectives.
Results of our experiment revealed that care must be taken while applying highly accepted well-understood properties of 2D and 3D visualizations to the spatio-temporal data. On one hand, none of the techniques was superior to the other in terms of task completion time except for some particular cases. On the other hand, our 2D density map implementation led to more accurate inferences for tasks related to trend detection and making comparisons, as vastly suggested by the previous work. As suggested by these examples, the validity of the generally accepted aspects of 2D and 3D visualization needs to be reconsidered for the analysis of spatio-temporal data, hence the purpose of our study.
Keywords: Spatio-Temporal Data, Density Map, Density Cube, 2D and 3D Visualizations.
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Paper 6
Transfer Function Refinement for Exploring Volume Data
Shengzhou Luo, John Dingliana
Trinity College Dublin
Abstract
Volume visualization is a powerful technique for depicting layered structures in 3D volume data sets. However, it is a major challenge to obtain clear visualizations of a volume with layers clearly revealed. In particular, the specification of the transfer function is frequently a time-consuming and unintuitive task in volume rendering. In this paper, we describe a global opti-mization and two user-driven refinement methods for modulating transfer functions in order to assist the exploration of volume data. This optimization is dependent on the distribution of scalar values of the volume data set and is designed to reduce general occlusion and improve the clarity of layers of structures in the resulting images. The user can explore a volume by interactively specifying different priority intensity ranges and observe which layers of structures are revealed. In addition we show how the technique can be applied for time-varying volume data sets by adaptively refining the transfer function based on the histogram of each time-step. Experimental results on various data sets are presented to demonstrate the effectiveness of our method.
Keywords: Transfer Function, Volume Rendering, Volume Visualization.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 7
Cloth Tearing Simulation
Emre Onal, Veysi Isler
Middle East Technical University
Abstract
Among different physical simulation topics, cloth simulation is one of the most popular subjects in computer graphics. There are many different studies published on different aspects of cloth simulation, but there are not many studies focused on the tearing of cloth. Existing studies related to this topic have only dealt with some aspects of the problem [Metaaphanon et al. 2009] and have not provided general solutions. In this study, we provide a generic solution for different aspects of the problem of tearing cloth.
Some of the points we focus on in this study include: providing realistic tearing effect, preserving polygonal area consistency and texture integrity after the process of tearing, and handling the tear properly for either outer physical impacts or inner manipulations like allowing a user to drag the cloth interactively.
The technique proposed in this paper works with non-uniform cloth structures. It makes it easier to adopt the solution proposed here for many different simulation systems. The processing cost of the technique is quite small, so it is also appropriate for real-time simulation systems.
Keywords: Cloth Tearing, Cloth Simulation, Spring Physics, Fracturing Materials.
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Paper 8
Simple Vertical Human Climbing Control with End Effector State Machines
Zümra Kavafoğlu1, Hacer İlhan1, Ersan Kavafoğlu1,
Haşmet Gürçay1, Tolga Çapın2
1Hacettepe University, 2TED University
Abstract
We present a framework for physics based vertical climbing control for human like articulated figures. In our work motion of end effectors of the figure are categorized under four states: Holding, Swinging, Reached and Gave-Up. Each end effector owns a finite state machine for managing the transitions between these states. Different target poses are determined for the limbs for swinging and holding states and they are tracked with PD Controller and gravity compensation. At Reached and Gave-Up states the aim of the end effector is to touch the closest point on the wall. Physics based movement of end effectors for touching the wall is simulated by using Jacobian Transpose Control. Our framework also includes a strategy manager which enables building different climbing strategies.
Keywords: Physics Based Animation, Climbing, Character Animation.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 9
Interacting with Boids in an Incompressible Fluid Environment
Aytek Aman, Ateş Akaydın, Uğur Güdükbay
Bilkent University
Abstract
With increasing power of the computing hardware, computer simulations are being realized in real-time. It is now possible to create real-life phenomena using computers. In this study, we present a crowd and fluid interaction environment, where fish in the environment depict flocking behaviour, affected by the flow of an incompressible fluid that can be manipulated by a Kinect Controller. This system can be used in virtual reality applications and video games to provide immersive underwater scenarios. We developed our application on a commercially available game engine that provides real-time experience for the users.
International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 10
A Dynamic Exit Choice Method for Real-Time Indoor Evacuation Scenarios
Oner Barut1, Murat Haciomeroglu2, Cumhur Y. Ozcan1, Hayri Sever1
1Hacettepe University, 2Gazi University
Abstract
Most of the evacuation simulations focus their at-tention to the accuracy of the simulation. Therefore, their models fail to provide real-time performance which is indispensable for almost all video games. In this paper, we propose a real-time crowd simulation model specifically designed for indoor evacuation scenarios to be used by entertainment systems. While agents in our model perform local collision avoidance using an agent-based steering technique, the optimal exit gates and the global paths to these gates are determined efficiently by the proposed system. We represent our simulation environment as a uniform grid and we perform Dijkstra path finding for all exit gates which computes shortest paths from all exit gates to all cells. Then, for each grid cell, we choose the exit gate having shortest path within all gates and assign this gate to the cell which means all agent in the grid cell will evacuate the area using the selected exit gate. Later on, we reverse the previously found paths between every grid cell and their associated exit gates in order to calculate guidance velocity of the agents in the cells. Our model takes advantage of the limited goal point availability by only performing one Dijkstra path finding per exit gate to further increase the efficiency of the simulation. Test results indicate that our method not only manages to balance the agent load on the exit gates despite non-uniform position distribution of the agents in the test scenarios, but also achieve lower average and maximum evacuation times than mostly used nearest gate selection approach.
Keywords: Evacuation, Exit Choice, Path Finding.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 11
Keep Brushing! Developing Healthy Oral Hygiene Habits in Young Children with an Interactive Toothbrush
Lal Gamze Bozgeyikli, Evren Can Bozgeyikli, Andrew Raij
University of South Florida
Abstract
Cravy Brush is an interactive toothbrush attachment that helps young children (3-8 years old) develop a daily habit of brushing teeth. The attachment displays an interactive game that provides real-time visual and auditory feedback. In addition to feedback, Cravy Brush also provides virtual rewards when children brush properly. Alarm feature calls for children to brush their teeth twice a day at desired times. We collect background data regarding tooth brushing sessions, which can be presented later on to parents.
In this paper, design and development of Cravy Brush and lessons learned are presented. As a starting point, we conducted a pilot test with one child for a week’s duration. Feedback from both parents and the child revealed that Cravy Brush made the tooth brushing experience more fun and was effective at encouraging the child to brush her teeth regularly for the dentist-recommended two minutes.
Keywords: Serious Games, Persuasive Games, Games For Health.
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Paper 12
3D Interactive Virtual Chemistry Laboratory for Simulation of High School Experiments
1University of Malakand, 2Universidade Federal de Santa Catarina
Abstract
In education laboratory is the main contrivance for students’ learning improvement. Therefore we developed a 3D interactive virtual chemistry laboratory (VCL) for chemistry experiments. This paper describes the potential contribution of the VCL in students’ learning improvement which is based on advanced 3D interaction interface. The aim of VCL is to provide more immersive virtual environment to users by using 3D interaction with chemical items and to simulate their chemistry experiments on high school level. This will increase the learning aptitudes of students in performing chemistry laboratory work. We evaluated the VCL by high school level students, which revealed that VCL is more useful for learning enhancement in chemistry education.
Keywords: Virtual Reality Environment, 3D Interaction, Virtual Laboratory.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
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Paper 13
Enhancing Gamepad FPS Controls with Tilt-Driven Sensitivity Adjustment
Gazihan Alankuş, Alp Arslan Eren
Izmir University of Economics
Abstract
Playing a first person shooter (FPS) game using a gamepad is inherently more difficult than playing it with a mouse. In this study, we propose a novel input method for gamepads to improve the FPS aim task. We take a user-centric approach to identify unused secondary motions to be indicative of players’ intents. We consider the gamepad tilt as a secondary motion that users naturally perform while playing with the gamepad, and interpret it as the intent of the user to move the FPS aim faster. We use a tilt sensor to detect the amount of tilt, and use it to increase the sensitivity of the gamepad analog joystick when the gamepad is tilted. We compare this to two other input methods: a pure gamepad and a tilt-aim scheme. Our experiments show that our approach is statistically better than the tilt-aim approach, and is comparable with the pure gamepad approach.
Keywords: Video Games, Gamepad, First Person Shooter, Tilt Input, Sensitivity Adjustment, Human-Computer Interaction.
EURASIA GRAPHICS 2014 International Conference on Computer Graphics, Animation and Gaming Technologies October 14, Hacettepe University Congress Centrum, Ankara, TURKEY
