Overview of crowd simulation in computer graphics

High-powered technology use computer graphics in education, entertainment, games, simulation, and virtual heritage applications has led it to become an important area of research. In simulation, according to Tecchia et al. (2002), it is important to create an interactive, complex, and realistic virtual world so that the user can have an immersive experience during navigation through the world. As the size and complexity of the environments in the virtual world increased, it becomes more necessary to populate them with peoples, and this is the reason why rendering the crowd in real-time is very crucial. Generally, crowd simulation consists of three important areas. They are realism of behavioral (Thompson and Marchant 1995), high-quality visualization (Dobbyn et al. 2005) and convergence of both areas. Realism of behavioral is mainly used for simple 2D visualizations because most of the attentions are concentrated on simulating the behaviors of the group. High quality visualization is regularly used for movie productions and computer games. It gives intention on producing more convincing visual rather than realism of behaviors. The convergences of both areas are mainly used for application like training systems. In order to make the training system more effective, the element of valid replication of the behaviors and high-quality visualization is added

ISSUES AND PROBLEMS IN BRAIN MAGNETIC RESONANCE IMAGING: AN OVERVIEW

There are many issues and problems in the brain magnetic resonance imaging (MRI) area that haven’t solved or reached satisfying result yet. This paper presents an overview of the various issues and problems of the segmentation, correction, optimization, description and their application in MRI. The overview is started by describing the segmentation properties that are the most important and challenging in MRI brain manipulation. Then correction for reconstructing the brain MRI cortex, classification is utilized to classify the segmented brain image, and also review the uses of description is the great prospecting issue while some neurologist need the information resulted from brain imaging process including their potential problems from application applied by each technique. In each case, it is provided some general background information

The development of local solar irradiance for outdoor computer graphics rendering

Atmospheric effects are approximated by solving the light transfer equation, LTE, of a given viewing path. The resulting accumulated spectral energy (its visible band) arriving at the observer’s eyes, defines the colour of the object currently on the line of sight. Due to the convenience of using a single rendering equation to solve the LTE for daylight sky and distant objects (aerial perspective), recent methods had opt for a similar kind of approach. Alas, the burden that the real-time calculation brings to the foil had forced these methods to make simplifications that were not in line with the actual world observation. Consequently, the results of these methods are laden with visual-errors. The two most common simplifications made were: i) assuming the atmosphere as a full-scattering medium only and ii) assuming a single density atmosphere profile. This research explored the possibility of replacing the real-time calculation involved in solving the LTE with an analytical-based approach. Hence, the two simplifications made by the previous real-time methods can be avoided. The model was implemented on top of a flight simulator prototype system since the requirements of such system match the objectives of this study. Results were verified against the actual images of the daylight skies. Comparison was also made with the previous methods’ results to showcase the proposed model strengths and advantages over its peers

Rendering process of digital terrain model on mobile devices

Digital Terrain Model has been used in many applications especially in Geographical Information System. However with the recent improvement in mobile devices that can support 3 Dimension (3D) content, rendering 3D based terrain on mobile devices is possible. Although mobile devices have improved its capabilities, rendering 3D terrain is tedious due to the constraint in resources of mobile devices. Furthermore, rendering DTM add more constraint and issues to the mobile devices. This paper focuses on the rendering process of DTM on mobile devices to observe some issues and current constraints occurred. Also to determine the characteristic of terrain properties that will affect the rendering performance. Experiments were performed using five datasets that derived from aerial images. The experimental results are based on speed of rendering and the appearance of the terrain surface. From these results, issues and problems that are highlighted in this paper will be the focus of future research

Path finding algorithms in game engine development

Commercial games are still growing and are a billion-dollar industry. Great graphics have been the vital factor to attract the user, and mostly the main driving forces for sales. However, it is no longer true. More realistic gaming experiences are also an important factor to make a game valuable in the market (Bj”ornsson, Y et al. 2003). Therefore, artificial intelligence has become more and more important nowadays. Artificial intelligence in game always relates to the character in game, which is able to think like human and behave like human beings. One of the artificial intelligence techniques which have been developed recent years is path finding. Path finding gives the best route for the game character to move from starting point to the goal destination

A review on level of detail

Recent 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. In this paper, 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 will be given

The development of spatio-temporal data model for dynamic visualization of virtual geographical information system

Virtual Geographical Information Systems (VGIS) is known to be one of the technologies used to improve the presentation of geographic visualization. Developing an efficient spatiotemporal data model is very important in contributing to the functionality improvement of the VGIS. Thus in this research, we focused on the data management aspect and has developed a suitable spatiotemporal data model for storing and retrieving volumetric geographic movement information. Volumetric is one type of spatial object in the VGIS, which is used to visualize 3D information. In order to develop real processes in VGIS, we have integrated the time element as an important factor to 3D objects. Time has been integrated with the data model, and temporal versions of volumetric surface data can be stored by using the model. This research also uses linear interpolating model techniques to visualize the movement changes. This application was implemented by developing a prototype visualization system using a Triangulation Irregular Network (TIN) with integrated time in the TIN structure. Result shows that the proposed data model is able to perform well with a visualization algorithm using linear interpolation and an improved TIN structure. This research contributed a suitable Spatiotemporal Data Model for managing continuous volume and 3D geographic movement data in VGIS and also a prototype of Spatiotemporal Database System which is can be implemented in GIS software. This can be particularly useful in applications such as geographic historical management data application, morphology of the terrain data, mobile movement, and Global Positioning System (GPS) application

Real-time shadow casting using fake soft shadow volume

Shadows are essential to realistic and visually appealing images, but they are difficult to compute in most display environments especially in computer games. Since the introduction of shadow volume by Crow (1977), shadow map by William (1978) and then fake shadows by Blinn (1988, 1996), a lot of development has been done to improve shadow algorithm in real-time graphic application. Current issues about shadow are on real-time dynamic soft shadows and hardware improvement that improvised real- time shadow generation