3D Object Representation for Physics Simulation Engines and its Effect on Virtual Assembly Tasks

2012 ◽  
Author(s):  
Germanico Gonzalez ◽  
Hugo I. Medellin ◽  
Theodore Lim ◽  
James M. Ritchie ◽  
Raymond C. W. Sung
Keyword(s):  
Collision Detection ◽  
Object Representation ◽  
Virtual Assembly ◽  
Detection Algorithm ◽  
Convex Decomposition ◽  
Virtual Objects ◽  
Detection Algorithms ◽  
Physics Simulation ◽  
Assembly Tasks ◽  
Simulation Engines

Physical based modelling (PBM) uses physics simulation engines (PSE) to provide the dynamic behaviour and collision detection of virtual objects in virtual environments emulating the real world. There exists a variety of PSEs, each one with pros and cons according to the application in which they are employed. Each physics engine uses its proprietary collision detection algorithm. Collision detection is a key aspect of assembly tasks and its performance is dependent on the way virtual objects are represented. In general, objects can be divided into two groups: convex and concave, the latter being the most common and challenging for collision detection algorithms. This study reports on three different methods to represent concave objects. GIMPACT, Hierarchical Approximate Convex Decomposition (HACD) and Approximate Convex Decomposition (ACD), which are evaluated and compared based on their collision detection performances. An exact convex decomposition algorithm, named as ConvexFT, is also proposed and analyzed in this paper. Finally the performance of the three existing methods and the ConvexFT proposed approach are compared in order to assess which model representation algorithm is best suited for haptic-virtual assembly tasks.

Physics Engines Evaluation Based on Model Representation Analysis

2014 ◽  
Author(s):  
Germánico González Badillo ◽  
Hugo I. Medellín Castillo ◽  
Theodore Lim ◽  
Víctor E. Espinoza López
Keyword(s):  
Virtual Environments ◽  
Dynamic Behavior ◽  
Collision Detection ◽  
Model Representation ◽  
Virtual Object ◽  
Virtual Objects ◽  
Physics Simulation ◽  
Representation Method ◽  
Assembly Tasks ◽  
Simulation Engines

Virtual environments (VE) are becoming a popular way to interact with virtual objects in several applications such as design, training, planning, etc. Physics simulation engines (PSE) used in games development can be used to increase the realism in virtual environments (VE) by enabling the virtual objects with dynamic behavior and collision detection. There exist several PSE available to be integrated with VE, each PSE uses different model representation methods to create the collision shape and compute virtual object dynamic behavior. The performance of physics based VEs is directly related to the PSE ability and its method to represent virtual objects. This paper analyzes different freely available PSEs — Bullet and the two latest versions of PhysX (v2.8 and 3.1) — based on their model representation algorithms, and evaluates them by performing various assembly tasks with different geometry complexity. The evaluation is based on the collision detection performance and their influence on haptic-virtual assembly process. The results have allowed the identification of the strengths and weaknesses of each PSE according to its representation method.

Haptic Rendering: Practical Modeling and Collision Detection

1999 ◽  
Author(s):  
ZhuLiang Cai ◽  
John Dill ◽  
Shahram Payandeh
Keyword(s):  
Surgical Training ◽  
Collision Detection ◽  
Object Representation ◽  
Virtual Assembly ◽  
Detection Algorithm ◽  
Haptic Rendering ◽  
3D Object ◽  
Modeling Techniques ◽  
Simulation Results ◽  
Fast Collision

Abstract 3D collision detection and modeling techniques can be used in the development of haptic rendering schemes which can be used, for example, in surgical training, virtual assembly, or games. Based on a fast collision detection algorithm (RAPID) and 3D object representation, a practical haptic rendering system has been developed. A sub-system determines detailed collision information. Simulation results are presented to demonstrate the practicality of our results.

Implementation and Evaluation of Mixed Model Representation of Virtual Objects in a Haptic Based Virtual Assembly Platform

2017 ◽  
Author(s):  
Germánico González Badillo ◽  
Hugo I. Medellín-Castillo ◽  
Víctor E. Espinoza López
Keyword(s):  
Mixed Model ◽  
Virtual Assembly ◽  
Model Representation ◽  
Dynamic State ◽  
Assembly System ◽  
Assembly Systems ◽  
Assembly Process ◽  
Virtual Objects ◽  
Physics Simulation ◽  
Simulation Engines

Virtual assembly systems have become popular in recent years due to its ability to simulate natural interaction between parts and ease of manipulation by the user. One of the most relevant technologies used in virtual assembly systems are haptic devices that provide force feedback and allow simulating real word conditions, such as weight, inertia, texture and collisions. Physics simulation engines (PSE) are another important tool used to simulate a realistic behavior in virtual assembly systems by enabling the effect of gravity and collision response of the virtual objects, resulting in a real world behavior. However, the use of haptic systems together with physics simulation engines is costly in terms of computing resources. This cost is mainly associated to collision detection between virtual objects, and increases when the shapes represented within the PSE are more complex, resulting in a poor performance of the virtual assembly system, making very difficult to simulate the assembly of complex parts or use several parts in the assembly. The present work shows a new algorithm to simulate complex objects, by using a different representation of the same object according with its dynamic state during the assembly process. The results show that the use of mixed model representation reduce the computing time when assembling objects, thus improving the performance of the virtual assembly system and finally allowing a better comfort and performance of the user during the assembly process. The system HAMS (Haptic Assembly and Manufacturing System) was used for the experimental validation, also the simulation of four assembly tasks that simulate real assembly objects, has been conducted.

Collision Detection

2011 ◽  
pp. 36-67
Author(s):  
Gabriel Zachmann
Keyword(s):  
Virtual Reality ◽  
Real Time ◽  
Collision Detection ◽  
Serious Games ◽  
Medical Training ◽  
Virtual Assembly ◽  
Virtual Objects ◽  
Enabling Technologies ◽  
Assembly Simulation ◽  
Physically Based

Collision detection is one of the enabling technologies in many areas, such as virtual assembly simulation, physically-based simulation, serious games, and virtual-reality based medical training. This chapter will provide a number of techniques and algorithms that provide efficient, real-time collision detection for virtual objects. They are applicable to various kinds of objects and are easy to implement.

Collision Detection Based on SIMD Model

2014 ◽  
Vol 519-520 ◽  
pp. 833-837
Author(s):  
Hui Yan Qu ◽  
Wei Zhao
Keyword(s):  
Real Time ◽  
Virtual Environment ◽  
Collision Detection ◽  
Time Complexity ◽  
Reconstruction Algorithm ◽  
Detection Algorithm ◽  
Data Selection ◽  
Iterative Sequence ◽  
The Public ◽  
Virtual Objects

In order to solve the virtual objects intersect problem in virtual environment, real-time fast CD application must be used in virtual environment. Collision detection algorithm based on a SIMD parallel was proposed. For ordered lists we used methods for N processors to search ordered sequence simultaneously, to select a valid range through an iterative, to retain the public segment as an iterative sequence so that to complete the division of the interval and data selection. It can improve the reconstruction of the bounding box of the data selected when these two algorithms applied to the detection of the CD. Experimental results show that compared with the classical reconstruction algorithm, the proposed algorithm has better time complexity and improve the efficiency of the CD.

Collision Detection Algorithm of Belt Grinding of the Blisk Based on Improved Octree Segmentation Method

2021 ◽  
Author(s):  
Zhi Huang ◽  
Xing Yang ◽  
Jie Min ◽  
Hongyan Wang ◽  
Pengxuan Wei
Keyword(s):  
Collision Detection ◽  
Clustering Algorithm ◽  
Detection Algorithm ◽  
Segmentation Method ◽  
Belt Grinding ◽  
Detection Model ◽  
Detection Algorithms ◽  
Bladed Disk ◽  
Abrasive Belt ◽  
Algorithm Verification

Abstract In the process of belt grinding aero-engine Blisk(Bladed Disk), the abrasive belt can easily interfere with the Blisk, which will damage the valuable Blisk. Therefore, it is indispensable and significant to study the collision detection of belt grinding the Blisk. However, the application of traditional collision detection algorithms in this complicated realistic scene is difficult to obtain satisfactory results. In order to improve the accuracy and efficiency of the collision detection of grinding the Blisk, a collision detection algorithm based on the improved octree segmentation method is proposed in this paper. Firstly, the Oriented Bounding Box (OBB) is applied to establish the collision detection model for the abrasive belt. Secondly, the traditional octree segmentation method is optimized based on the k-means clustering algorithm, and an improved octree segmentation method is presented, in addition, the flow chart of the collision detection algorithm for belt grinding of the Bliskis given. Finally, algorithm verification and experimental verification are carried out based on a certain type of the Blisk. The results suggest that compared with the traditional method, the method in this paper not only promotes the accuracy of collision detection, but also promotes the efficiency of collision detection, and meets the requirements of object collision detection in this tanglesome scene with both accuracy and speed.

DESIGN AND APPLICATION OF BOUNDING VOLUME HIERARCHY COLLISION DETECTION ALGORITHM BASED ON VIRTUAL SPHERE

2019 ◽  
Vol 19 (07) ◽  
pp. 1940044
Author(s):  
MONAN WANG ◽  
SHAOYONG CHEN ◽  
QIYOU YANG
Keyword(s):  
Collision Detection ◽  
Detection Efficiency ◽  
Vastus Lateralis ◽  
Detection Algorithm ◽  
Virtual Surgery ◽  
Vastus Lateralis Muscle ◽  
Detection Algorithms ◽  
Bounding Volume ◽  
High Detection Efficiency ◽  
Bounding Volume Hierarchy

The result of collision detection is closely related to the further deformation or cutting action of soft tissue. In order to further improve the efficiency and stability of collision detection, in this paper, a collision detection algorithm of bounding volume hierarchy based on virtual sphere was proposed. The proposed algorithm was validated and the results show that the detection efficiency of the bounding volume hierarchy algorithm based on virtual sphere is higher than that of the serial hybrid bounding volume hierarchy algorithm and the parallel hybrid bounding volume hierarchy algorithm. Different collision detection algorithms were tested and the results show that the collision detection algorithm based on virtual sphere has high detection efficiency and good stability. As the number of triangular patches increased, the advantage was more and more obvious. Finally, the proposed algorithm was applied to two large and medium-sized virtual scenes to implement the collision detection between the vastus lateralis muscle, thigh and surgical instrument. Based on the virtual sphere, the collision detection algorithm of bounding volume hierarchy can implement efficient and stable collision detection in a virtual surgery system. Meanwhile, the algorithm can be combined with other acceleration algorithms (such as the multithread acceleration algorithm) to further improve detection efficiency.

A Collision Detection Algorithm in Virtual Assembly Technology

2015 ◽  
Vol 713-715 ◽  
pp. 411-414
Author(s):  
He Qun Qiang ◽  
Chun Hua Qian
Keyword(s):  
Collision Detection ◽  
Classical Problem ◽  
Virtual Assembly ◽  
Detection Algorithm ◽  
Research Field ◽  
Component Model ◽  
Detection Problem ◽  
Tree Algorithm ◽  
Assembly Technology ◽  
Shape Characteristics

The collision detection problem is a classical problem in computer graphics research field. It has become a hot topic in recent years with the development of virtual assembly technology. And accurate collision detection is crucial to improve the reliability and authenticity of virtual assembly. In this paper, we designed a collision detection algorithm with a pre-segment strategy based on OBB-Tree algorithm, took advantage of the shape characteristics of component model, used a smaller bounding box for operation. Experimental results showed that the efficiency of the algorithm is about 10% higher than that of traditional OBB-Tree algorithm.

Collision Detection Using the GJK Algorithm

2012 ◽  
pp. 253-288 ◽  
Author(s):  
William N. Bittle
Keyword(s):  
Collision Detection ◽  
Detection Algorithm ◽  
Ray Casting ◽  
Detection Algorithms ◽  
Continuous Collision Detection

GJK is a fast and elegant collision detection algorithm. Originally designed to determine the distance between two convex shapes, it has been adapted to collision detection, continuous collision detection, and ray casting. Its versatility, speed, and compactness have allowed GJK to be one of the top choices of collision detection algorithms in a number of fields.

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