Tawaf crowd simulation using reciprocal velocity obstacle

Studies on crowd simulation have been around us for nearly 30 years. It remains one of the important and fundamental fields in three-dimensional (3D) computer graphics. Simulating large amount of crowds such as the crowd during Hajj is never an easy task. Therefore, a more refined technique is needed to avoid the entities, agents or characters in Hajj crowd from colliding with each other. In order to simulate such a huge crowd, the reciprocal velocity obstacles concept is used. The simulation is made using the reciprocal velocity obstacles as the collision avoidance technique. An experiment with up to 200 pilgrims is then conducted on four different personal computers (PCs) with different specifications

Towards a realistic marker-based augmented reality scene: issues and prospective aspect

This paper describes the main problems in realistic Augmented Reality scenes. In order to view the real world with additional computer-generated information in a seamless and realistic integration, there are several research challenges that can be identified; some related to camera tracking, system design, user interaction, and rendering. The focus on each of these aspects was thoroughly explored by several methods and techniques. This study is considered to be an exploration for an Augmented Reality rendering technique. This technique focuses on increasing the realism in the AR scene. Thus, in order to realize the AR scene in a more realistic way, there are four main issues; light source detection, well-designed virtual objects that can have true reflex of the real environment, then integration of a real-time accurate soft shadow

An Overview on Base Real-Time Shadow Techniques in Virtual Environments

Shadows are elegant to create a realistic scene in virtual environments. Variety types of shadow techniques encourage us to prepare an overview on all base shadow techniques. Non real-time and real-time techniques are big subdivision of shadow generation. In non real-time techniques ray tracing, ray casting and radiosity are well known and deeply described. Radiosity implemented to create very realistic shadow on non real-time scene. Although traditional radiosity algorithm is difficult to implement, we have proposed a simple one. The proposed pseudo code is easier to understand and implement. Ray tracing used to prevent of collision of movement objects. Projection shadow, shadow volume and shadow mapping are used to create real-time shadow in virtual environments. We have used projection shadow for some objects are static and have shadow on flat surface. Shadow volume used to create accurate shadow with sharp outline. Shadow mapping that is the base of most recently techniques is reconstructed. The reconstruct algorithm gives some new idea to propose another algorithm based on shadow mapping.  

A study on image segmentation techniques used in color detection

to humans, an image is a meaningful arrangement of regions and objects, whereas to computers, an image is merely a random collection of pixels. This work exploits some of the techniques based on the extraction of the color of an image in the real-time environment. Image segmentation is an intense research area in Computer Vision, however, enhancements or results still on to produce accurate segmentation results for images. Relating with other surveys that compare multiple techniques, this paper takes the advantage to select of the most used technique(s), Our study may be helpful for Augmented Reality environment, object detection and tracking as well as other real -time technologies. Interested reader will obtain know ledge on various categories and types of research challenges In the image-based segmentation within the scope of colored images environments

Atmospheric cloud modeling methods in computer graphics: A review, trends, taxonomy, and future directions

The modeling of atmospheric clouds is one of the crucial elements in the natural phenomena visualization system. Over the years, a wide range of approaches has been proposed on this topic to deal with the challenging issues associated with visual realism and performance. However, the lack of recent review papers on the atmospheric cloud modeling methods available in computer graphics makes it difficult for researchers and practitioners to understand and choose the well-suited solutions for developing the atmospheric cloud visualization system. Hence, we conducted a comprehensive review to identify, analyze, classify, and summarize the existing atmospheric cloud modeling solutions. We selected 113 research studies from recognizable data sources and analyzed the research trends on this topic. We defined a taxonomy by categorizing the atmospheric cloud modeling methods based on the methods' similar characteristics and summarized each of the particular methods. Finally, we underlined several research issues and directions for potential future work. The review results provide an overview and general picture of the atmospheric cloud modeling methods that would be beneficial for researchers and practitioners

An Approach to Minimising Estimated Pincushion Camera Distortions

 Minimizing camera distortion has been a focus of recent photorealism researches. Of the several types of camera distortions, researchers concentrated on the radial distortion being the most severe part of the total lens aberrations. Often, polynomial approximations by introducing distortion-specific parameters into the camera model have been methods of evaluating distortions. Of the two types of radial distortions, barrel, is the most discussed probably because of its dominance in cheap wide-angle lenses. In this paper, an approach to estimating and minimizing pincushion distortion by using fundamental surface area properties of the distorted image is proposed. This paper is significant as it reveals the importance of the topic and its implications on the camera. Demonstrations using four camera lenses show the robustness of this technique under different focal lengths conditions. The reliability of the approach is justified by comparing the results with the physical observations using (two tailed) t-test statistic.

Voice search for Quranic verses recitation

This paper describes challenges and solutions for building a successful voice search system as applied to Quranic verses. The paper describes the techniques used to deal with an finite vocabulary how modelling completely in the voice domain for language model and dictionary can avoid some system complexity, and how we built dictionaries, language and acoustic models in the framework. The Holy Quran is written in Arabic language, and the Arabic is one of the oldest languages In the world that presents its own features and challenges while searching for Arable-based content. The most search systems for the Holy Quran Is organized around text words (contained in the target verses) but no system organized around voice while there is need to search in quranic recitation. The speech recognition approaches are applied to build the dictionary and test the system, while the MFCC and stemming techniques will be will be applied to find the stem of the word. The development of voice search for Quranic recitation led to a significant simplification of the original process to build a system to retrieving audio information related to the Qur'an, it also helps to build a system to serve people with special needs such as bllnd,paralyzed, and others who can not use the keyboard