Mohd Shahrizal Sunar

A Review on Augmented Reality for Virtual Heritage System

Augmented reality is one of the emerging technologies to reconstruct the historical building and monument in the previous era, where the user experiences with the real environment or virtual scene. In education, Virtual Heritage becomes as a platform of learning, motivating and understanding of certain events and historical elements for the students and researchers. The significance of reconstruction of digital culture heritage are to preserve, protect and interpret of our cultural and history. In recent year, there are a number of significant researches and techniques that have been developed, which is focusing on virtual restitution of historical sites. This paper will present an overview on augmented reality in Virtual Heritage system and also consists with the explanation of techniques to reconstruct the historical sites.

A comprehensive study on pathfinding techniques for robotics and video games

This survey provides an overview of popular pathfinding algorithms and techniques based on graph generation problems. We focus on recent developments and improvements in existing techniques and examine their impact on robotics and the video games industry. We have categorized pathfinding algorithms based on a 2D/3D environment search. The aim of this paper is to provide researchers with a thorough background on the progress made in the last 10 years in this field, summarize the principal techniques, and describe their results. We also give our expectations for future trends in this field and discuss the possibility of using pathfinding techniques in more extensive areas.

Survey of Shadow Volume Algorithms in Computer Graphics

Abstract This study will provide an overview of popular and famous algorithms and techniques in shadow generation based on shadow volumes. It characterizes well-known techniques, describing each of them in detail, and discusses the advantages and drawbacks of each. Basic ideas, improvements, and future works of the techniques are also comprehensively summarized and analyzed in depth. Often, programmers have difficulty selecting an appropriate shadow generation algorithm based on shadow volumes that is specific to their purpose. We have classified and systemized these techniques. The main goal of this paper is to provide researchers with background on a progress of shadow volume techniques so as to make it easier for researchers to choose the method best suited to their aims. It is also hoped that our analysis will help researchers find solutions to the shortcomings of each technique.

Computer Generated Caricature: A Survey

Caricature is a pictorial representation of a person or subject in summarizing way by exaggerating the most distinctive features and simplifies the common features in order to make that subject different from others and at the same time, preserve the likeness of the subject. Computer Generated Caricature is developed in order to assist the user in producing caricature automatically or semi-automatically. It is derived from the rapid advance in computer graphics and computer vision and introduced as a part of computer graphics’ non-photo realistic rendering technologies as well. Recently, Computer Generated Caricature becomes particularly interesting research topic due to the advantageous features of privacy, security, simplification, amusement and their explosive emergent real-world application such as in magazine, digital entertainment, Internet and mobile application. On the basis of the previous facts, this paper surveys the uses of caricature in variety of applications, theories and rules in the art of drawing caricature, how these theories are simulated in the development of caricature generation system and the current research trend in this field. Computer generated caricature can be divided into two main categories based on their input data type: human centered approach and image processing approach. Next, process of generating caricature from input photo is explained briefly. It also reported the state of the art techniques in generating caricature by classifying it into four approaches: interactive, regularity-based, learning-based and predefined database of caricature illustration. Lastly, this paper will discuss relevant issues, problems and several promising direction of future research.

Covering photo-realistic properties of outdoor components with the effects of sky color in mixed reality

Outdoor rendering is an attractive topic in computer graphics. In this paper our main concern is to reveal the interaction between sky color and virtual objects in Mixed Reality environments. Although registration and tracking are two of the main issues in building effective Augmented Reality (AR) systems the creation of more realistic virtual objects indistinguishable from their real-world counterparts is our target which is currently the ultimate goal in AR. Two classes of sky color generation are employed to reveal the outdoor-element interaction. Virtual Sky Modelling (VSM) based on the Perez Model is capable of generating the sky color in a specific location, date and time. The second technique is to generate a virtual model based on the real image of the sky which is called in this paper Real Sky Modelling (RSM). Subsequently, preprocessing of the sky color bleeding is based on the radiosity technique to give the sky color effect to the virtual objects as well as the real ones. Through designing a test AR set-up and applying software and hardware the goal of a robust generation of realistic virtual objects with effect of sky color is achieved.

A Study on Natural Interaction for Human Body Motion Using Depth Image Data

This paper explains a study on natural interaction (NI) in human body motion using depth image data. It involves about overview of NI and depth image data. Human body motion is a non-verbal part for interaction or movement that can be used to involves real world and virtual world. Furthermore, interaction with computer or machine can be more realistic as real world and becoming more important to academic researchers, game industries, and can be adapt to other field like mechanical engineering for robotics movement and surgery purpose in medical area. Functional taxonomies will show step-by-step how human body motion were detected and created a skeleton joint. Also, we discuss about technologies behind Kinect for Xbox 360 (Kinect). Recent research in this area also included.

Realistic Real-Time Outdoor Rendering in Augmented Reality

Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

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.

A quadratic spline approximation using detail multi-layer for soft shadow generation in augmented reality

Implementation of shadows is crucial to enhancement of images in AR environments. Without shadows, virtual objects would look floating over the scene resulting in unrealistic rendering of AR environments. Casting hard shadows would provide only spatial information while soft shadows help improve realism of AR environments. Several algorithms have been proposed to render realistic shadows which often incurred high computational costs. Little attention has been directed towards the balanced trade-off between shadow quality and computational costs. In this study, two approaches are proposed: Quadratic Spline Interpolation (QSI) to soften the outline of the shadow and Detail Multi-Layer (DML) technique to optimize the volume of computations for the generation of soft shadows based on real light sources. QSI estimates boarder hard shadow samples while DML involves three main phases: real light sources estimation, soft shadow production and reduction of the complexity of 3-Dimensional objects’ shadows. To be more precise, a reflective hemisphere is used to capture real light and to create an environment map. The Median Cut algorithm is implemented to locate the direction of real light sources on the environment map. Subsequently, the original hard shadows are retrieved and a sample of multilayer hard shadows is produced where each layer has its unique size and colour. These layers overlap to produce soft shadows based on the real light sources’ directions. Finally, the Level of Details (LOD) algorithm is implemented to increase the efficiency of soft shadows by decreasing the complexity of vertex transformations. The proposed technique is tested using three samples of multilayer hard shadows with varying numbers of light sources generated from the Median Cut algorithm. The experimental results show that the proposed technique successfully produces realistic soft shadows at low computational costs.