A review of particle damping modeling and testing

Resumen es: Los fotocatalizadores han abierto las puertas a multiples aplicaciones en ciencia y medicina, entre ellas el TiO2 en presencia de luz ultravioleta UV-A s...

Ingeniería y Competitividad

Performing accurate and precise collision detection method between objects in virtual environment application such as computer games and medical simulation is important in computer graphics research and development. Given pair of objects that near colliding, numerous mechanic has been developed by researchers in order to minimize computation time and increase accuracy of the detection. However, most of these techniques required a lot of computational cost, extra processing power and complex algebraic equations just to solve distance between near colliding objects. In this paper, we described an alternate technique, which is a theoretical framework of novel technique in order to find the optimum closest distance between two or more convex polyhedral in virtual environment application. Given pair of near colliding objects, we proposed an easy to implement mechanism using dynamic origin point by creating inner and middle Axis Aligned Bounding-Box just to find closest distance between objects. We believed that the technique is suitable to be used in any game engine tools for computer games and medical simulation.

Distance computation using axis aligned bounding box (AABB) parallel distribution of dynamic origin point

As an effective tool for simulating spatiotemporal urban processes in the real world, urban cellular automata (CA) models involve multiple data layers and complicated calibration algorithms...

A minimum-volume oriented bounding box strategy for improving the performance of urban cellular automata based on vectorization and parallel computing technology

The invention relates to a composite bounding box algorithm based on AABB and OBB self adaption. Firstly, a direction axis included angle threshold value eps is set; then the center position m of a bounding box is calculated through peak coordinates and index data; a covariance matrix C is calculated; feature vectors of the covariance matrix C are obtained and unitized to serve as three directional axes of a part; the included angles theta1, theta2 and theta3 between the three direction axes of the part and standard coordinate axes X, Y and Z are calculated respectively; finally, the theta1, theta2 and theta3 are compared with the given threshold value eps, if the theta1, theta2 and theta3 are all smaller than equal to the given threshold value eps, the AABB bounding box is adopted, the length, width and height of the AABB bounding box are calculated, and the AABB bounding box is established according to the center m; if one included angle is larger than the given threshold value eps, the OBB bounding box is established according to the center position m and the rotating angles defined in the specification around the standard coordinate axes. The composite bounding box algorithm can adaptively select an AABB method or an OBB method to establish the part bounding box according to actual features of a three-dimensional part model, good flexibility is achieved, and a certain intelligence level is achieved.

Composite bounding box algorithm based on AABB and OBB self adaption

A hierarchical model for collision detection of convex polyhedral is presented. This model is based on double representation: the exterior is composed by the minimum outer boxes that envelope the polyhedral; it is an Axis-Aligned Bounding Boxes (AABB), and the interior is composed by the maximum inner boxes that is included inside the polyhedral. Inner boxes allow faster testing of overlapping detection and outer boxes allow faster testing of no-collision. The double representation model proposed has been structured as a binary tree, the polyhedral has been subdivided and the original polyhedral is reconstructed by all nodes of equal level of the tree. Experimental results show that inner boxes improve the collision detection process; consequently, the efficiency of the collision detection is improved. The collision detection algorithm has been implemented and validated with a set of convex polyhedral. Finally, a comparison among the proposed algorithm and some recognized collision detectors has been done.

Collision detection model based on Bounding and containing Boxes

A bounding volume is a common method to simplify object representation by using the composition of geometrical shapes that enclose the object; it encapsulates complex objects by means of simple volumes and it is widely useful in collision detection applications and ray tracing for rendering algorithms They are popular in computer graphics and computational geometry Most popular bounding volumes are spheres, Oriented-Bounding Boxes (OBB's), Axis-Aligned Bounding Boxes (AABB's); moreover, the literature review includes ellipsoids, cylinders, sphere packing, sphere shells, k-DOP's, convex hulls, cloud of points, and minimal bounding boxes, among others A Bounding Volume Hierarchy is usually a tree in which the complete object is represented tighter fitting every level of the hierarchy Additionally, each bounding volume has a cost associated to construction, update, and interference tests For instance, spheres are invariant to rotation and translations, then they do not require being updated; their constructions and interference tests are more straightforward then OBB's; however, their tightness is lower than other bounding volumes Finally, three comparisons between two polyhedra; seven different algorithms were used, of which five are public libraries for collision detection

A literature review of bounding volumes hierarchy focused on collision detection

A bounding volume is a common method to simplify object representation by using the composition of geometrical shapes that enclose the object; it encapsulates complex objects by means of simple volumes and it is widely useful in collision detection applications and ray tracing for rendering algorithms. They are popular in computer graphics and computational geometry. Most popular bounding volumes are spheres, Oriented-Bounding Boxes (OBB’s), Axis-Aligned Bounding Boxes (AABB’s); moreover, the literature review includes ellipsoids, cylinders, sphere packing, sphere shells,k-DOP’s, convex hulls, cloud of points, and minimal bounding boxes, among others. A Bounding Volume Hierarchy is usually a tree in which the complete object is represented tighter fitting every level of the hierarchy. Additionally, each bounding volume as a cost associated to construction, update, and interference tests. For instance, spheres are invariant to rotation and translations, then they do not require being updated; their constructions and interference tests are more straightforward then OBB’s; however, their tightness is lower than other bounding volumes. Finally, three comparisons between two polyhedra; seven different algorithms were used, of which five are public libraries for collision detection.

Revisión de literatura de jerarquía volúmenes acotantes enfocados en detección de colisiones

Bounding Volume Hierarchies for Rigid Bodies

A model for collision detection based on double hierarchical spherical representation is proposed in this paper: an outer spherical representation for detecting no-intersections and an inner spherical representation in order to improve the performance of the collision detector. The algorithm has been implemented. Several tests were conducted with convex polyhedral and the performance of the algorithm was evaluated in terms of the collision between inner spheres. The experimental results show that outer spheres have been useful to determine lack of intersection, whereas inner spheres are more efficient for detecting existence of intersection and for speeding up the process of detecting collision. Using inner spheres improve the general performance because it reduces the number of intersection tests between the faces of the polyhedral. Collision detection, Spherical representation, Convex polyhedron.

Simena Dinas

Papers

Collision detection model based on Bounding and containing Boxes

A literature review of bounding volumes hierarchy focused on collision detection

Revisión de literatura de jerarquía volúmenes acotantes enfocados en detección de colisiones

Bounding Volume Hierarchies for Rigid Bodies

Un detector de colisiones jerárquico basado en esferas exteriores e interiores A hierarchical collision detector based on outer and inner spheres