Norhaida Mohd Suaib

Oriented convex polyhedra for collision detection in 3D computer animation

This paper presents a method for fast-approximate collision detection between 3D models S undergoing rigid body motion. To enclose a 3D model in as tight as possible, we propose an approach known as oriented convex polyhedra R(S). By surrounding the 3D models tightly, the veracity of detected collision can be improved. It is known that the large number of empty corners which belongs to any 3D bounding volumes B(S) can affect the truthfulness of collision detection. Therefore, we describe a way to compute R(S) using intersection of a set of halfspaces. The directions of these halfspaces are generated from calculating covariance matrix. To acquire the tightest R(S) as possible, we have improved the quality of abutting corners by implementing similar approach as Tribox Bounds method. In our case, improvements of abutting corners are important since the generated intersection points will be used for intersection testing. To detect collision between R(S), we utilize local space of R(S) and perform a straightforward approach by simply checking its interval pairs. Our proposed approach was implemented and we perform a number of comparisons in terms of time and recorded collision with other B(S). From the conducted tests, R(S) performs well and might be a possible choice for detecting collisions of the 3D models undergoing rigid body motion.

Balanced hierarchical construction in collision detection for rigid bodies

Performing collision detection between rigid bodies in virtual environment is always the common problem for researchers. Determination of a precise contact within appropriate time response can eventually end up with only one option that collision detection can support which is either speed or accuracy. For most three-dimensional (3D) application, discrete collision detection (DCD) is the most preferable compared to continuous collision detection (CCD) as it creates fast response. DCD commonly used hierarchical representation in order to create space volume representing an object. Hence, in this paper we introduce a technique called Split Object Median Splitting (SOMS) that improves the hierarchical representation of 3D object in order to create fast collision detection method suitable for 3D application such as games and animations. The experimental result shows that our method has the ability to construct well-balanced Bounding-Volume Hierarchies (BVH) tree.

Bounding-Volume Hierarchies Technique for Detecting Object Interference in Urban Environment Simulation

Performing and detecting object interference or collision detection in urban environment simulation is always challenging problem for researchers to come out with fast and efficient collision detection algorithm. Most of previous method seems trying to tackle the problems of involving specific geometric models colliding pairs with restricted rules and guidelines. For example, convex hull bounding-volume tends to solve the collision detection problems by make the collision more accurate. However, its limitation of performing fast collision detection method must be left behind. Hence, in this paper we introduce new traversal algorithm using Bounding-Volume Hierarchies (BVH) for collision detection in urban environment simulation. By using hierarchical approach, the efficiency of detecting object interference in urban simulation is increase. We believe that BVH method can be useful in urban simulation for collision detection between static rigid models and dynamic rigid models. Thus it should be able to overcome the equipment of urban environment simulation. Our result shows that bounding-volume hierarchies achieve favorable frame-rates in real time simulation using top-down binary tree. In practice, the construction of bounding-volume hierarchies in urban environment simulation are not just useful for collision detection but they also useful for others detecting object interference technique such culling and raytracing.

On Faster Bounding Volume Hierarchy Construction for Avatar Collision Detection

In many interactive computer graphics applications, users are represented as virtual characters called avatars. Collision detection is a pre-requisite in interactive computer graphics application so that appropriate response and realistic behaviour can be generated. However, it will not be easy to anticipate collisions since objects’ motion are dependant on user interaction and avatar manipulation. Ideally, collision detection needs to be done efficiently, with accurate result in the shortest time possible. However, due to its computationally intensive nature, collision detection could cause a bottleneck to the system. A variety of techniques, data structures and algorithms were proposed to accelerate the collision detection process. Acceleration data structures are widely used not only to promote faster collision detection, but also in the field of ray tracing and deformable objects simulation. This paper discusses the use of bounding volume hierarchy as an acceleration data structure in collision detection for avatar in virtual environment, as well as similar methods used in interactive ray tracing and deformable objects simulation. Based on these findings, method for fast bounding volume hierarchy construction is proposed as a first step towards efficient avatar collision detection.

Motion Graph for Character Animation: Design Considerations

Animating human character has become an active research area in computer graphics. It is really important for development of virtual environment applications such as computer games and virtual reality. One of the popular methods to animate the character is by using motion graph. Since motion graph is the main focus of this research, we investigate the preliminary work of motion graph and discuss about the main components of motion graph like distance metrics and motion transition. These two components will be taken into consideration during the process of development of motion graph. In this paper, we will also present a general framework and future plan of this study.

Fast Traversal Algorithm for Detecting Object Interference Using Hierarchical Representation between Rigid Bodies

Searching for fast and efficient algorithm to perform collision detection between static and moving objects is always fundamental problems in virtual environment. Most of previous method seems trying to tackle the problems of involving specific geometric models colliding pairs with restricted rules and guidelines. For example, convex hull bounding-volume tends to solve the collision detection problems by make the collision more accurate. However, its limitation of performing fast collision detection method must be left behind. In this paper, we introduce new traversal scheme using depth first search algorithm called earlier node detection algorithm. This algorithm automatically performs simultaneously for child nodes intersection compared to root intersection test. Result shows that our algorithm works perfectly for rigid models when performing collision detection. In practice, the new traversal algorithms helps improve the situation of determine two or more collision between rigid models especially in urban simulation.

Solid deformation modeling techniques

Non-rigid solid object deformations techniques have been widely used in the computer graphics community to simulate and animate deformable objects. Both offline and real time applications have already benefited from deformation techniques evolutions. This paper discusses the most popular geometric deformation techniques used for both real time and offline applications such as virtual surgery and motion pictures. Deformations techniques are divided into two sub deformation type which is non-physical based deformations and physical based deformations.

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.