Showing papers on "Physics engine published in 2011"

Modular open robots simulation engine: MORSE

Abstract: This paper presents MORSE, a new open-source robotics simulator. MORSE provides several features of interest to robotics projects: it relies on a component-based architecture to simulate sensors, actuators and robots; it is flexible, able to specify simulations at variable levels of abstraction according to the systems being tested; it is capable of representing a large variety of heterogeneous robots and full 3D environments (aerial, ground, maritime); and it is designed to allow simulations of multiple robots systems. MORSE uses a “Software-in-the-Loop” philosophy, i.e. it gives the possibility to evaluate the algorithms embedded in the software architecture of the robot within which they are to be integrated. Still, MORSE is independent of any robot architecture or communication framework (middleware). MORSE is built on top of Blender, using its powerful features and extending its functionality through Python scripts. Simulations are executed on Blender's Game Engine mode, which provides a realistic graphical display of the simulated environments and allows exploiting the reputed Bullet physics engine. This paper presents the conception principles of the simulator and some use-case illustrations.

Using game engines for physical based simulations a forklift

Abstract: The detailed simulation of construction operations remains a challenging task in construction practice. A tremendous number of labor-hours are required to set key frames of an animation step-by-step and considerable computational power is needed to render an animation frame-by-frame. This research aims to utilize a game engine, which has been a rapidly evolving field for over a decade, to reduce the effort required by developers. The process of developing a construction simulation was separated into three main steps: 3D model construction, setup of physical properties, and creation of interactive logic. The Blender game engine was selected as the implementation tool, and a forklift simulation was created to demonstrate the concept. With a keypad, users could control a virtual forklift to simulate the manipulation of an actual forklift. The simulation result shows the advantages of developing a game engine-based construction simulation. The quality of the simulation’s graphics provides a high degree of realism, and the interactivity requirements between user and computer are satisfied.

Simulating multi-million-robot ensembles

Abstract: Various research efforts have focused on scaling modular robotic systems up to millions of cooperating devices. However, such efforts have been hampered by the lack of prototype hardware in such quantities and the unavailability of accurate and highly scalable simulations. This paper describes a simulation framework for such systems, which can model the execution of distributed software and the physical interaction between modules. We develop a scalable, multithreaded version of an off-the-shelf physics engine, and create a software execution engine that can efficiently harness hundreds of cores in a cluster of commodity machines. Our approach is shown to run 108x faster than a previous scalable simulator, and permit simulations with over 20 million modules.

ARGoS: a Pluggable, Multi-Physics Engine Simulator for Heterogeneous Swarm Robotics

Abstract: We present a novel robot simulator called ARGoS. The main focus of ARGoS is the real-time simulation of massive heterogeneous swarms of robots. In contrast to existing robot simulators, which obtain scalability by imposing limitations to the extent and accuracy of the robot models, in ARGoS we pursue a deeply modular approach that allows the user both to add custom features easily and to allocate computational resources where needed by the experiment at hand. In this respect, a unique feature of ARGoS is the possibility to use multiple physics engines for different parts of the environment. The physics engines can be of different kinds and robots can migrate from one to another in a transparent way. This feature enables a whole new set of optimizations to improve scalability and paves the way for a new approach to parallelism in robotic simulation. Results show that ARGoS can simulate about 10,000 wheeled robots with full dynamics in real-time. We discuss possible improvements to the architecture of ARGoS to achieve simulations of millions of entities in

Analysis of contemporary robotics simulators

Abstract: Designing a robot physically and validating it at every step is an arduous task. Contemporary robotics simulators can help to achieve laborious physics simulations, 3D visualizations, virtual robot modeling and novel research work that save time and money. Simulators are written in numerous programming languages like C, C++, Java, C# and other OOP languages that decide their platform compatibility. Some robot simulators use physics engines like ODE, Karma Engine for better simulation that include responses like collision detection, scene representation and rigid body simulations. Some use sophisticated 3D graphic aids like OpenGL and Graphic cards (NVidia, ATI) rather than traditional Direct3D, considering various facets like cost, portability and extensions. Codes can be transferred to the real robots from some simulators after proper verification for their operation. Unlimited features like multiplayer, controllers transference over networks, ‘special effects’ and so forth, keep on pouring. This paper proffers some of the widespread commercial/ open-source simulators for robots and UAVs used in market. Further, I conclude that any kind of robot including legged, wheeled or UAVs can be simulated using simulators available in market with continuous endeavors to upgrade these simulators.

Physics Engine Systems Using "Force Shadowing" For Forces At A Distance

Abstract: New physics engine systems and related media and products implementing a “Force Shadowing” effect from ambient, uniformly distributed background energy, to describe or simulate forces at a distance are provided.

LocoTest: deploying and evaluating physics-based locomotion on multiple simulation platforms

Abstract: In the pursuit of pushing active character control into games, we have deployed a generalized physics-based locomotion control scheme to multiple simulation platforms, including ODE, PhysX, Bullet, and Vortex. We first overview the main characteristics of these physics engines. Then we illustrate the major steps of integrating active character controllers with physics SDKs, together with necessary implementation details. We also evaluate and compare the performance of the locomotion control on different simulation platforms. Note that our work only represents an initial attempt at doing such evaluation, and additional refinement of the methodology and results can still be expected. We release our code online to encourage more follow-up works, as well as more interactions between the research community and the game development community.

Method and system for assisting in the handling of robotized machines in a congested environment

Abstract: A method for handling of a first robotized mobile machine moving in a congested working environment under the control of a second robotized mobile machine, providing the operator, in real time, with a relevant view of the working scene, even if an object intrudes into the field of view of the camera and thereby obscures the operator's view. This method is based on use of properties of a physics engine of the constraint resolution type. For each object in the scene, the physics engine has a physical representation of said object in the form of a mesh. The engine calculates a wrench on the basis of the respective positions and velocities of two objects. In case of a collision between the manipulator and a fixed object in the scene, the engine determines the wrench to be applied to the manipulator in order to make it avoid the object.

PAC-C3D: A New Software Architectural Model for Designing 3D Collaborative Virtual Environments

Abstract: We propose PAC-C3D as a new software model for 3D Collaborative Virtual Environments (CVE). This model merges the results from two research fields: distribution models for CVE and HCI design for computer-supported cooperative work. PAC-C3D proposes to describe each part of a shared virtual object through explicit interfaces to ensure a strong separation between the core functions of a virtual environment, its (visual) representations, and its collaborative features such as synchronization and consistency maintenance between remote users. PAC-C3D makes it possible to design a CVE with low dependency between the core functions, the distribution mode and the 3D graphics API used. It explicitly deals with the main distribution modes encountered in CVE. It makes it easy to use different 3D graphics API for different nodes involved in the same collaborative session, providing interoperability between these 3D graphics API. It also makes it possible to integrate other kinds of 3D representations such as physics engines into the CVE.

A fast collision detection algorithm suitable for complex virtual environment

Abstract: A fast algorithm of collision detection based on projection feedback and surface extraction was proposed. In the pre-processing stage of this algorithm, we make the triangles elements which take part in the precise collision detection reduce greatly by dividing the space with the method of projection feedback and extracting the surface cell of the collision body with the method of surface extraction. In the precise collision detection stage, we subdivide the extracted surface cells by using the OBB bounding box in order to make the collision detection more precise. Finally, the calculation speed of the precise collision detection is accelerated by using the parallel computing. Experiment results show that the algorithm is more efficiency and accuracy over other current typical collision detection algorithm.

Rendering of 3D dynamic virtual environments

Abstract: In this paper we present a framework for the rendering of dynamic 3D virtual environments which can be integrated in the development of videogames. It includes methods to manage sounds and particle effects, paged static geometries, the support of a physics engine and various input systems. It has been designed with a modular structure to allow future expansions.We exploited some open-source state-of-the-art components such as OGRE, PhysX, ParticleUniverse, etc.; all of them have been properly integrated to obtain peculiar physical and environmental effects. The stand-alone version of the application is fully compatible with Direct3D and OpenGL APIs and adopts OpenAL APIs to manage audio cards.Concluding, we devised a showcase demo which reproduces a dynamic 3D environment, including some particular effects: the alternation of day and night influencing the lighting of the scene, the rendering of terrain, water and vegetation, the reproduction of sounds and atmospheric agents.

Novative rendering and physics engines to apprehend special relativity

Abstract: Relativity, as introduced by Einstein, is regarded as one of the most important revolutions in the history of physics. Nevertheless, the observation of direct outcomes of this theory on mundane objects is impossible because they can only be witnessed when relative velocities close the speed of light are involved. These effects are so counterintuitive and contradicting with our daily understanding of space and time that physics students find it hard to learn Special Relativity beyond mathematical equations and to understand the deep implications of the theory. Although we cannot travel at the speed of light for real, Virtual Reality makes it possible to experiment the effects of relativity in a 3D immersive environment. Our project is a framework designed to merge advanced 3D graphics with Virtual Reality interfaces in order to create an appropriate environment to study and learn relativity as well as to develop some intuition of the relativistic effects and the quadri-dimensional reality of space-time. In this paper, we focus on designing and implementing an easy-to-use game-like application : a carom billiard. Our implementation includes relativistic effects in an innovative graphical rendering engine and a non-Newtonian physics engine to treat the collisions. The innovation of our approach lies in the ability i) to render in real-time several relativistic objects, each moving with a different velocity vector (contrary to what was achieved in previous works), ii) to allow for interactions between objects, and iii) to enable the user to interact with the objects and modify the scene. To achieve this, we implement the 4D nature of space-time directly at the heart of the rendering engine, and develop an algorithm allowing to access non-simultaneous past events that are visible to the observers at their specific locations and at a given instant of their proper time. We explain how to retrieve the collision event between the pucks and the cushions of the billiard game and we show several counterintuitive results for very fast pucks. The effectiveness of the approach is demonstrated with snapshots of videos where several independent objects travel at velocities close to the speed of light, c.

Research and improvement of collision detection based on oriented bounding box in physics engine

Abstract: Collision detection algorithm can improve the realistic and immersion of 3D scene, is becoming one of the researches in the field of Virtual Reality. At present, in large and complex scenes, traditional collision detection algorithms exist the problems of low detection efficiency and poor accuracy. In view of above question, this paper manage to combine the Sphere with the OBB method, that is, first calculating preliminarily by Sphere, exclude objects do not intersect obviously; then calculating accurately, find the collision object. Experimental results show that, Compared with the ordinary OBB algorithm, this algorithm can significantly improve the efficiency and accuracy of collision detection. It proves that the improved collision detection algorithm has practical value.

Research and Application for Collision Detection Algorithm in Virtools

Abstract: Collision detection is an important part of the development in virtual reality system. In this paper, we describe the principle, realization of AABB (axis-aligned bounding boxes) collision detection algorithm and three-dimensional frame (3D Frame) collision detection algorithm. AABB bounding box algorithm is a small amount of testing speed. Three-dimensional frame collision detection method is calculating the distance between rays to determine whether the objects collide in a certain time slice. Both methods can handle different situations of collision detection. The paper also gives the application using the Virtool's graphical development engine, two algorithms to solve the collision detection in drilling simulation system. Finally, the whole system can be found to achieve the desired effect of the collision, and collisions are also able to control the accuracy within the system to meet the requirements of authenticity.

A Mobile Robot Simulator Using a Game Development Engine

Abstract: This work presents the implementation issues arising from the development of a mobile robot simulator by using a game development engine. The developed simulator takes advantage of the graphics engine and of the physics engine available in the video game development platform. We show how the use of these tools enable us to obtain realistic simulations in the execution of robotic tasks including sensing and motion primitives. We will describe the elements composing the mobile robot simulator and how they were verified in some robotic tasks simulated in the application developed. We will also present the main issues arising in the development process.

Simulation of Soft Tissue Deformation in Virtual Surgery Based on Physics Engine

Abstract: In this paper, the simulation of soft tissue deformation in real-time virtual surgical systems is introduced and analyzed and physics engine is lead to solve the contradiction between the precision of simulation and real time in computing of soft tissue deformation. A real-time soft tissue deformation module based on the physics engine PhysX is designed in this paper. In this paper, a tetrahedral mesh production algorithm is used to generate finite element models, which can describe the soft tissue details, and a linear viscoelastic model(Kelvin model) is used to replace simple linear elastic model, which can generate viscoelastic finite element model and improve the biofidelity of virtual surgery. Furthermore, using smooth particle hydrodynamics module to simulate blood, the real-time interaction between soft tissue and blood is implemented.

Haptic Rendering in Interactive Applications Developed with Commodity Physics Engine

Abstract: Availability of commodity physics engines such as PhysX’s nVidia has significantly reduced the effort required for developing interactive applications concerning the simulation of the physical world. However, it becomes a problem when force feedback is needed since the addition of haptic rendering into these applications is non-trivial. The issues include the high haptic update rate and the inaccessibility of force data in the physics engine. In the paper, we tackle the first issue by mediating the update-rate disparity between haptic rendering and other processes by data buffering, and the second issue by calculating the force feedback indirectly using the engine’s collision geometry data. The major benefit of these techniques is that they enable a homogeneous development environment where the same engine can be used for both the physics and haptic simulation. Furthermore, integration of force feedback into physics-engine based applications would not introduce significant changes into developer’s codebase. The proposed techniques have potential to streamline the development of demanding applications such as virtual surgical simulation and immersive computer gaming.

Phusis studio: A real-time physics engine for solid and fluid simulation

Abstract: Along with the development of virtual reality and digital games, the dynamic virtual scenes become more and more complex. Real-time simulation of massive fluid and solid bodies is a challenge in common PC machine. We use the three layer design for the physics engine, so performance optimization can be done apart. Collision detection of solid and fluid is the most common component is this platform. Then solid simulation of fracture, deformation, clothing and fluid simulation of liquid, gas, fire, tornado have been implemented in this engine. Finally, a visual content generation system that is built on this engine can be used by animators to produce physics animation. Also, the physics engine supports APIs for real-time simulation applications.

Interactive simulation of a virtual environment

Abstract: A distributed simulation system is composed of simulator stations linked over a network that each renders real-time video imagery for its user from scene data stored in its data storage. The simulation stations are each connected with a physics farm that manages the virtual objects in the shared virtual environment based on their physical attribute data using physics engines, including an engine at each simulation station. The physics engines of the physics farm are assigned virtual objects so as to reduce the effects of latency, to ensure fair fight requirements of the system, and, where the simulation is of a vehicle, to accurately model the ownship of the user at the station. A synchronizer system is also provided that allows for action of simulated entities relying on localized closed loop controls to cause the entities to meet specific goal points at specified system time points.

Application of semantic maps for mobile robot simulation

Abstract: In this paper a new concept of using semantic map for robot operator training purpose is described. The approach consists of 3D laser data acquisition, semantic elements extraction (using image processing techniques) and transformation to rigid body simulation engine, therefore the State Of the Art related to those research topics will be discussed. The combination of a 2D laser range finder with a mobile unit was described as the simulation of a 3D laser range finder in [1]. In this sense we can consider that several researches are using so called simulator of 3D laser range finder to obtain 3D cloud of points [2]. The common 3D laser simulator is built on the basis of a rotated 2D range finder. The rotation axis can be horizontal [3], vertical [4] or similarly to our approach (the rotational axis lies in the middle of the scanners field of view). Semantic information extracted from 3D laser data is recent research topic of modern mobile robotics. In [5] a semantic map for a mobile robot was described as a map that contains, in addition to spatial information about the environment, assignments of mapped features to entities of known classes. In [6] a model of an indoor scene is implemented as a semantic net. This approach is used in [7] where robot extracts semantic information from 3D models built from a laser scanner. In [8] the location of features is extracted by using a probabilistic technique (RANSAC). Also the region growing approach [9] extended from [10] by efficiently integrating k-nearest neighbor (KNN) search is able to process unorganized clouds of points. The semantic map building is related to SLAM (Simultaneous Localization And Mapping) problem [11]. Most of recent SLAM (Simultaneous Localization And Mapping) techniques use camera [12], laser measurement system [13] or even registered 3D laser data [14]. Concerning the registration of 3D scans described in [15] we can find several techniques solving this important issue. The authors of [16] briefly describe ICP (Iterative Closest Points) algorithm and in [17] the probabilistic matching technique is proposed. In [18] the mapping system that acquires 3D object models of man-made indoor environments such as kitchens is shown. The system segments and geometrically reconstructs cabinets with doors, tables, drawers, and shelves, objects that are important for robots retrieving and manipulating objects in these environments. A detailed description of computer based simulators for unmanned vehicles is shown in [19] [57]. Also in [20] the comparison of real-time physics simulation systems is given, where a qualitative evaluation of a number of free publicly available physics engines for simulation systems and game development is presented. Several frameworks are mentioned such as USARSim which is very popular in research society [21], Stage, Gazebo [22], Webots [23], MRDS (Microsoft Robotics Developer Studio) [24]. Some researchers found that there are many available simulators that offer attractive functionality, therefore they proposed a new simulator classification system specific to mobile robots and autonomous vehicles [25]. A classification system for robot simulators will allow researchers to identify existing simulators which may be useful in conducting a wide variety of robotics research from testing low level or autonomous control to human robot interaction.. To ensure the validity of robot models, NIST proposes standardized test methods that can be easily replicated in both computer simulation and physical form [26]. In this paper we propose a new idea of semantic map building, this map can be transformed into rigid body simulation. It can be used for several applications such as robot operator training. It is a new idea and can give an opportunity to develop training systems composed by real and virtual robots. We hope that it will improve multi robot system design and development. The paper is organized as follows: in section “Robot” robot and its data acquisition module is described. In section “Semantic map approach” we explained the semantic map concept applied to walls and stairs detection. Section “Semantic simulation engine” describes the core of proposed simulation system. The final discussion is given in the “Conclusion”.

Parallelizing a real-time physics engine using transactional memory

Abstract: The simulation of the dynamics and kinematics of solid bodies is an important problem in a wide variety of fields in computing ranging from animation and interactive environments to scientific simulations. While rigid body simulation has a significant amount of potential parallelism, efficiently synchronizing irregular accesses to the large amount of mutable shared data in such programs remains a hurdle. There has been a significant amount of interest in transactional memory systems for their potential to alleviate some of the problems associated with fine-grained locking and more broadly for writing correct and efficient parallel programs. While results so far are promising, the effectiveness of TM systems has so far been predominantly evaluated on small benchmarks and kernels. In this paper we present our experiences in parallelizing ODE, a realtime physics engine that is widely used in commercial and open source games. Rigid body simulation in ODE consists of two main phases that are amenable to effective coarse-grained parallelization and which are also suitable for using transactions to orchestrate shared data synchronization. We found ODE to be a good candidate for applying parallelism and transactions to - it is a large real world application, there is a large amount of potential parallelism, it exhibits irregular access patterns and the amount of contention may vary at runtime. We present an experimental evaluation of our implementation of the parallel transactional ODE engine that shows speedups of up to 1.27x relative to the sequential version.

Numerical Modelling and Visualization of the Evolution of Extensional Fault Systems

Abstract: The purpose of this work is split into two categories, the first was to analyse the application of real-time Physics Engine software libraries for use in calculating a geological numerical model. Second was the analysis of the applicability of glyph and implicit surface based visualization techniques to explore fault systems produced by the model. The current state of the art in Physics Engines was explored by redeveloping a Discrete Element Model to be calculated using NVIDIA's PhysX engine. Analyses regarding the suitability of the engine in terms of numerical accuracy and developmental capabilities is given, as well as the definition of a specialised and bespoke parallelisation technique. The use of various glyph based visualizations is explored to define a new standardised taxonomy for geological data and the MetaBall visualization technique was applied to reveal three dimensional fault structures as an implicit surface. Qualitative analysis was undertaken in the form of a user study, comprising of interviews with expert geologists. The processing pipeline used by many Physics Engines was found to be comparable to the design of Discrete Element Model software, however, aspects of their design, such as integration accuracy, limitation to single precision floating point and imposed limits on the scale of n-body problem means their suitability is restricted to specific modelling cases. Glyph and implicit surface based visualization have been shown to be an effective way to present a geological Discrete Element Model, with the majority of experts interviewed able to perceive the fault structures that it contained. Development of a new engine, or modification of one that exists in accordance with the findings of this thesis would result in a library extremely well suited to the problem of rigid-body simulation for the sciences.

Collision Detection of TriangleMeshes using GPU

Abstract: Collision detection in physics engines often use primitives such as spheres and boxes since collisions between these objects are straightforward to compute. More complicated objects can then be mod ...

GKJ and clustering based algorithm for collision detection on deformable body

Abstract: this paper proposed a collision detection method for deformable body based on clustering algorithm and GKJ algorithm. This method first divide triangle meshes into convex hulls formed by multiple clusters; then utilizes GJK algorithm to solve the convex hull collision detection problem. The proposed method can increase detection efficiency, solve penetration problem, which happens when one body is small compared with triangle mesh, and provide freedom to set collision detection precision. Real-world applications provided feasibility and reliability of using this method in solving deformable body-to-body multi-points collision detection problems. It is valuable for researches in fields including 3D gaming, visual reality, physical simulation and others.

Integration of a Physics Engine into an Adventure Game Platform

Abstract: This paper presents the challenges and possibilities that arise from the inte gration of a 2D physics engine into an adventure game platform (i.e. engine and editor). This integration allows the use of a complex physics model within a narrative environment, thus increasing expressiveness and educational potential (through re-usability and increased challenge). In this work eAdventure is used as the adventure game platform and Box2D is used as the physics engine. While adventure games have been successfully applied in educational contexts from language learning to medicine, including a physics engine broadens the number of subjects that can be covered, thus increasing the scope and potential of the resulting games. This paper shows how such integration was implemented, and shows several mini-games that use the physics engine to provide visualization of physical experiments and attempt to increase player engagement. The mini-game approach allows for the easy integration of these new physics-based interactive scenarios within an adventure game narrative, where each mini-game can represent a puzzle or challenge to be solved.

Application of PhySX physics engine in virtual-reality-based astronaut training system

Abstract: A simulation method based on PhysX physics engine was designed in this paper for motion simulation of human body and objects in virtual-reality-based astronaut training system.A drivable virtual human model was established by using PhysX physics engine combined with data glove and motion tracking devices.The collision detection between human body and spacecraft as well as objects were implemented,and the computation of haptic force,the interaction interface between PhysX and force feedback device were also implemented.At last the simulation experiment was conducted.The simulation results demonstrate that the methods developed in this paper can effectively simulate the motion of human body and objects which enhance the immersion and reality of virtual-reality-based astronaut training system.

HUBOT--A Modeling and Simulation Platform Based on PhysX for Multi-link Robot

Abstract: This paper presents HUBOT - a modeling and simulation platform specialized for multi-link robots. We use PhysX as the dynamics solver so that we can manipulate various physics parameters of the robot directly. Visualization is also supported based on OpenGL rendering environment. HUBOT solves kinematics and dynamics among the robot and the environment, sensor data simulation is also implemented to help evaluate robot status and test control algorithms. A biped walking simulation of a humanoid robot is presented as a demonstration of our simulation platform.

Simulation of Bridge Collapse in Virtual Scene Based on Finite Element Analysis

Abstract: To replicate the scene of bridge collapse realistically, accurately and completely, this paper proposes a scene simulation method of bridge collapse based Finite Element (FE) analysis. On the basis of suitable scene model of bridge, 3D animation of bridge collapse is implemented by the callback of graphics engine Open Scene Graph (OSG) and special effects of bridge collapse are also created by physics engine physX. In addition, terrain and surroundings are added into the scene simulation. The collapse animation proves to be consistent with FE simulation by comparison and the scene simulation is more realistic and complete due to the special effects and the rich scene. This study provides an important reference for analysis of collapse accidents of bridges.