Daut Daman

A review on level of detail

Advances in modern 3D scanning technology and the increasingly size of computer simulations have led to a rapid increase in the availability and size of geometry data sets. Gigantic polygonal data sets, consisting of hundreds of millions of faces, are becoming quite common. While the performance of graphics hardware also seen a drastic rise in these years, however, ability to produce enormous data sets overload the capabilities of the state-of-the-art graphics chip. Therefore, automatic model simplification and run-time level of detail (LOD) management techniques are introduced. We present a review on level of detail techniques in an organized structure. Level of detail framework, level of detail management, level of detail simplification models and metrics for simplification and error evaluation are discussed in sequence. Finally, some current issues and conclusion are given.

Survey on Real-Time Crowds Simulation

The simulation of human massive crowds play an important role in real-time application such as games and walkthrough system. This kind of applications can provide an immersive feeling of life into the static scene and enhance the reality of the system. In recent years, there are many significant research and techniques have been developed, mainly focus on the entertainment industry for both real-time and non-real time rendering. This paper will give an overview on crowd behavior in real-time crowd simulation. The work will also cover numerous crowd modeling and rendering techniques.

The feasibility of human haptic emotion as a feature to enhance interactivity and immersiveness on virtual reality game

Interactivity and immersiveness are important keys on exploration virtual reality game. Numerous researchers concentrate to augment visual acuity in order to get sensible visualization and animation. In addition, acoustic has also became other aspects to enhance immersiveness of virtual reality game. Recently, there is an issue involving haptic as part of stimulating interactivity between virtual characters and players in order to obtain more attention from players. This paper presents the feasibility of how human haptic emotion being applied in virtual reality game. The idea is that through a haptic device the human emotion is sent to the game engine in order to gain more interactivity and immersiveness. The role of the device is to act as a bridge to deliver emotion sense from virtual character interaction into players from the sense of touch side. We classify each emotion into several different magnitude frequencies that are generated from the haptic devices. The intention of the classification is to tell players about the virtual character emotion during the playing period. This approach will be of great benefit in making virtual reality game more lively and impressive.

E-Facetic: the integration of multimodal emotion expression for avatar through facial expression, acoustic and haptic

Latest 3D humanoid models are merely able to produce emotion sensations through facial animation, gesture and voice. However, few of them are really concerned about manipulating haptic tactile emotion through vibration, especially on expressing 3D humanoid model emotion using common haptic device like joystick. In this paper, we have created a mapping approach to classify force power of vibration into particular emotion appearance. To justify our mapping process, the happiness mode is converted into low to medium vibration with short and long duration. The conducted experiment found out that the RGB values (1-255) can easily be mapped into given magnitude force (0-10000) as suggested by vibration frequency classification. The experiments give significant positive result which is able to drive avatar to give more realistic expression. All users have strong confidence rate on differentiating and recognizing emotion of users. From the user testing, we obtained 67% user give strong and very strong impression that our system gives stronger emotional expression than Alfred systems. 29 % user gives medium values to our system compare to Alfred system. Finally, around 5% users said that our system provides a little impression than Alfred system. Furthermore, we have found an interesting finding that all users agree that high vibration of joystick equivalent to anger emotion. Experiments also proved that user manages to have strong feeling and impression while they interact and communicate with EFACETIC. In the future, we believed that our proposed procedure will enhance the presence of avatar in the overall aspects of virtual reality, games or even serious games.

A spatiotemporal database prototype for managing volumetric surface movement data in virtual GIS

Virtual GIS have the capability to present geographic features in three-dimension. This will contribute to increasing user understanding of phenomena that occurred in certain areas. Virtual GIS need to include temporal element in the system for managing dynamic phenomena to simulate real process. Spatiotemporal database system can be used to manage temporal data or spatial data that involve changes. In this paper, we present the database system of a spatiotemporal database prototype for managing volumetric surface movement; Volumetric Surface Movement Spatiotemporal Data Model that has the ability to store changes of the surface data of a three dimensional object. Formalization of the surface movement phenomena on the volumetric object were defined. This model has been implemented using relational database model which store only the changing points in order to ensure an efficient data management. We have developed a visualization tool with the database system to visualize movement on the surface. The prototype system of this model has been tested and found to be efficient.

Face-Touch: An Emotional Facial Expression Technique of Avatar Based on Tactile Vibration in Virtual Reality Game

Nowadays we can see that avatar expresses their emotional expressions only by using facial animation, gesture and voice. In this research, we present an avatar in a creative way that can attract user attention while they play game and use computer. Human representations like virtual Assistants or virtual humans in the virtual environment are considered as an interface that can make harmonious relationships between human and computer (Wang et al., 2005). A virtual representation of human is expected to become a guideline in the virtual environment. Therefore, studies of artificial psychology have been conducted to create an interface that is able to comply with human satisfaction while they interact with computer. Considering this situation, we can see numerous applications such as Second Life or games like the SIMS manipulates a lot of avatars in their systems. If we look at this matter carefully, the substance of presence, which is the ultimate features for virtual environment application, requires further improvement. The root of the problem is caused by several factors such as: the complexity of virtual human model itself, emotional expression (Wang et al., 2005), or incoherent animation reaction(Rojas et al., 2008). Usually emotion is expressed by facial expression, voice intonation or even using hand gesture. Researchers in image processing and computer graphics fields tried to combine facial expression with voice expression and hand gesture. Recently Haptics or ‘sense of touch’ attracted attention to be explored especially Haptics that is related to emotional expression (Bailenson et al., 2007, Hashimoto and Kajimoto, 2008). In this study, our major concern is to grasp the ways to utilise haptic tactile vibration as an emotional expression of virtual human or avatar that can give the user more sensation during the interactions process. The procedure starts by mapping the human emotion colour diagram into several vibration frequencies. Considering this scenario, a group of frequencies are initiated as a magnetize stimulation to express particular emotional expression such as anger or happiness.

Facetouch: An innovative way to feel sensation of avatar emotional expression through sense of touch and facial appearance

Current and existing avatars are only able to express their emotional expressions only by using facial animation, gesture and voice. Yet, only few researchers successfully combined haptic tactile with human emotion expression. In this paper, we present an avatar in a creative way that can gain user attention while they play game and use computer. Our proposed technique is achieved through combination of visual sense and systematic mapping of sense of touch. The mapping procedure is developed by systemically map the emotion layer into color spectrum based on the standard color emotion theories. To prove our solution, we benchmark our proposed technique prototype with existing system like Alfred. From the conducted experiment, we found that 57% respondents feel strong expression of virtual head emotion expression when dedicated haptic device stimulates their sensory nerve. Using our design solution, we can see that psychological signal can be adapted with vibration characteristic.

QuadR-Tree Indexing Selection Engine for Tuning Spatial Database System using Mobile Geographical Information System Technology

The latest Mobile GIS technology is probable to manage the spatial components of daily business project, in the corporate database, and to apply proper geographic analysis efficiently in a desktop-focused application. This technology uses wireless internet for transferring process of spatial data from server to Mobile GIS or vice versa. However, the problem in wireless Internet is system bottlenecks that can slow down in the process of transferring data. One of the reasons why system bottlenecks could happen in this situation is because the spatial data is too large. The database design therefore is the most important part that must be considered. Database systems are now expected to be self-managing, self healing, and always-up. Another parts which also contribute in this problem are network, application server and web server (Kwan & Shi, 2002).

Hierarchical Approach for Fast and Efficient Collision Detection in Urban Simulation

Urban simulation research has become an important research area in computer graphics due to the need to visualize urban environment as realistic as possible. Urban environment consists of elements such as culling, lighting, shadows, collision detection and others that will determine the realism level of simulation. One of the key components that need further consideration is to equip the synthetic world with fast and efficient collision detection approach so that urban simulation can be done realistically. In general, hierarchical approach provides fast and efficient collision detection method in urban simulation. We present a new traversal algorithm of Bounding-Volume Hierarchies (BVH) for collision detection (CD) between static and moving object that can be used in urban simulation. The result from the experiments had shown that the combination of the AABB BVH and optimized traversal algorithm is superior over the previous BVH approaches where less time taken to detect collision between static and moving objects in urban simulation.

A design consideration of neuron 3D reconstruction visualization for neuronal morphology

Virtual neuron is tool that able to provide an extensive neuron cell visualizing and lab-experimenting experience. Its development requires combination efforts of informatics and neurosciences in order to create data acquisition, databasing and computational tool. The requirement to reconstruct neuron model towards greater realism still remains as an essential challenge in biological computing and visualization as to provide abroad appearance of neuron knowledge distribution. This paper enlightens on the ability of computational neuronal modeling as a powerful tool for exploring greater understanding in neurons developmental processes and structure-function relationships. By this finding, we proposed a design consideration that believes can generate a neuron model with successful and equivalent as per available neuron biological form requirement based on validation from existing neuron visualization. In this proposal, we apply the reconstruction model in generating virtual neuronal morphology integrated with Gouraud shading technique to perform smooth lighting on visualization surface presentation.