Research of the Wheat Modeling Problems Based on Creator

2014 ◽  
Vol 551 ◽  
pp. 696-701
Author(s):  
Fei Wang ◽  
Rui Juan Chi ◽  
Zhong Xiang Zhu ◽  
En Rong Mao
Keyword(s):  
Virtual Reality ◽  
Geometric Model ◽  
Three Dimensional ◽  
Behavioral Model ◽  
Virtual Experiment ◽  
Classical Dynamics ◽  
Agricultural Machinery ◽  
Geometry Model ◽  
Hydraulic Steering ◽  
Realistic Scenes

In order to making the virtual experiment results close to or equivalent to the real environmental effects, in addition to model realistic scenes, also need more accurate dynamic model. In this paper, based on research of hydraulic steering paddy and wheat combine harvester, first, used three-dimensional geometric model transformation technology to convert Pro/E model to a identified geometric model in VP virtual reality systems, second, used classical dynamics equations to build the mathematical model of this vehicle dynamics, finally, used VC++ programs to connect this two models, constructed a behavioral model of complete physics properties. This behavior model is not only more realistic than the geometry model in motion, but also it follows the laws of physics movement. It can effectively strengthen the authenticity of virtual experiment, provide an important platform to start agricultural machinery virtual characteristics test, and this Modeling Method can provide a reference for other agricultural machinery virtual reality platform to build.

Research of Agricultural Machinery Modeling Method Based on Virtual Reality

2014 ◽  
Vol 541-542 ◽  
pp. 684-689
Author(s):  
Fei Wang ◽  
Rui Juan Chi ◽  
Zhong Xiang Zhu ◽  
En Rong Mao
Keyword(s):  
Virtual Reality ◽  
Mathematical Models ◽  
Geometric Model ◽  
Three Dimensional ◽  
Behavioral Model ◽  
Modeling Method ◽  
Classical Dynamics ◽  
Agricultural Machinery ◽  
Virtual Test ◽  
Combine Harvester

In order to make the virtual experiment results close to or equivalent to the real movement patterns, the agricultural machinery virtual test based on virtual reality requires realistic scene model and it also needs more accurate agricultural machinery dynamic model.As for the rice and wheat combine harvester of hydraulic steering, firstly, model transformation technology is used to convert Pro/E harvester model into three-dimensional geometric model that can be identified by Vega Prime virtual reality systems. Secondly, classical dynamics equation is used to construct the mathematical models of the rice and wheat combine harvester. Finally, mathematical models are combined with geometric models by VC++ programming, and then the physical behavioral model of combine harvester which has the physics properties is created.It can effectively strengthens the authenticity of agricultural machinery virtual test, and provides an important platform to start agricultural machinery virtual characteristics test. The modeling method can provide an important agricultural machinery dynamic model for the further virtual test based on virtual reality.

scholarly journals Optimization and Simulation of Virtual Experiment System of Human Sports Science Based on VR

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Gaixin Li
Keyword(s):  
Virtual Reality ◽  
Motion Tracking ◽  
Tracking System ◽  
Three Dimensional ◽  
Human Motion ◽  
Flow Diagram ◽  
Virtual Experiment ◽  
Experiment System ◽  
Sports Science ◽  
Motion Tracking System

Virtual reality technology is an emerging technology developed on the basis of information technology. It is widely used in military, medical, mining, entertainment, and other fields. Therefore, many countries have been vigorously conducting research in recent years. As one of the important components of the virtual reality system, the three-dimensional human motion tracking system is of great significance to the research of practical virtual reality systems. It introduces the measurement principle of the spatial three-dimensional coordinate dynamic measurement device and discusses in detail the ultrasonic transmission, reception, amplification, filtering, comparison, shaping circuit, and single-chip interface circuit. This paper introduces the working principle and characteristics of the virtual experiment system and gives the structure diagram, hardware schematic diagram, and software flow diagram of the system. We mainly study the method of tracking human motion by measuring the three-dimensional coordinates of the space point, which lays a good foundation for the research of the actual three-dimensional motion tracking system. At the same time, the three-dimensional human body modeling is discussed, and the interactive movement policy of the human arm is briefly introduced. It has a certain effect on the actual virtual reality human-computer interaction system.

Study of Micro-Structure Based Effective Thermal Conductivity of Graphite Foam

2016 ◽  
Author(s):  
Yue Chai ◽  
Xiaohu Yang ◽  
Xiangzhao Meng ◽  
Qunli Zhang ◽  
Liwen Jin
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Effective Thermal Conductivity ◽  
Analytical Model ◽  
Geometric Model ◽  
Three Dimensional ◽  
Heat Sinks ◽  
High Porosity ◽  
Geometry Model ◽  
Graphite Foam

As a new type of functional material, porous graphite foam exhibits unique thermal physical properties and geometric characteristics in heat transfer applications. It has the advantages of low density, high specific surface area, high porosity and high bulk thermal conductivity, which can be used as the core component of small, lightweight, compact and efficient heat sinks. Effective thermal conductivity serves one of the key thermophysical properties for foam-cored heat sinks. The complex three-dimensional topology and interstitial fluids significantly affect the heat conduction through such kind of porous structures, reflecting a topologically based effective thermal conductivity. This paper presents a novel geometric model for representing the microstructure of graphite foams, with simplifications and modifications made on the actual pore structure of graphite foam. For calculation simplicity, we convert the realized geometry consisting of complex surfaces and tortuous ligaments into a simplified geometry with circular ligaments joined at cuboid nodes, on the basis of the volume equivalency rule. The multiple-layer method is used to divide the proposed geometry into solvable areas and the series-parallel relations are used to derive the analytical model for effective thermal conductivity. To physically explore the heat conduction mechanisms at pore scale, direction numerical simulations were conducted on the reconstructed geometric model. Achieving good agreement with experimental data, the present analytical model (based on the simplified geometry) is validated. Further, the numerically simulated conductivities follow the model prediction, favoring thermally that the two geometries are equal. The present geometry model is more realized and capable of reflecting the internal microstructure of graphite foam, which will benefit the understandings for the thermo-physical mechanisms of pore-scaled heat conduction and micro structures of graphite foam.

Geometry Information Extraction from the STEP Neutral File

2012 ◽  
Vol 433-440 ◽  
pp. 3158-3162
Author(s):  
Hai Peng Pan ◽  
Hao Feng
Keyword(s):  
Geometric Model ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Dynamic Link Library ◽  
Systematic Analysis ◽  
Geometry Model ◽  
Key Technologies ◽  
Cad Cam ◽  
Dynamic Link

It is one of the key technologies for the integration of CAD/CAM/CAPP to extract the geometric model information. Based on a systematic analysis and comprehension on the expression of STEP geometry model, the map between EXPRESS and C++ was studied. The module of map has been developed as a dynamic link library, which facilitated the expansion of system. In order to ensure the coherence and availability of collected data, a module for data acquisition has also been designed. The reading and analysis for STEP neutral file has been realized so that the geometry information in the STEP-based three-dimensional model could be extracted. Application illustration, which is used for supporting the slicing process in rapid prototyping, has been also presented. The method put forward in the paper is conducive to the integration of different CAX systems.

scholarly journals Immersive 3D virtual reality imaging in planning minimally invasive and complex adult cardiac surgery

2020 ◽  
Vol 1 (1) ◽  
pp. 62-70
Author(s):  
Amir H Sadeghi ◽  
Wouter Bakhuis ◽  
Frank Van Schaagen ◽  
Frans B S Oei ◽  
Jos A Bekkers ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Virtual Reality ◽  
Cardiac Surgery ◽  
Heart Surgery ◽  
Preoperative Planning ◽  
Operating Time ◽  
Three Dimensional ◽  
Cardiothoracic Surgery ◽  
Planning Tool ◽  
Computed Tomography Images

Abstract Aims Increased complexity in cardiac surgery over the last decades necessitates more precise preoperative planning to minimize operating time, to limit the risk of complications during surgery and to aim for the best possible patient outcome. Novel, more realistic, and more immersive techniques, such as three-dimensional (3D) virtual reality (VR) could potentially contribute to the preoperative planning phase. This study shows our initial experience on the implementation of immersive VR technology as a complementary research-based imaging tool for preoperative planning in cardiothoracic surgery. In addition, essentials to set up and implement a VR platform are described. Methods Six patients who underwent cardiac surgery at the Erasmus Medical Center, Rotterdam, The Netherlands, between March 2020 and August 2020, were included, based on request by the surgeon and availability of computed tomography images. After 3D VR rendering and 3D segmentation of specific structures, the reconstruction was analysed via a head mount display. All participating surgeons (n = 5) filled out a questionnaire to evaluate the use of VR as preoperative planning tool for surgery. Conclusion Our study demonstrates that immersive 3D VR visualization of anatomy might be beneficial as a supplementary preoperative planning tool for cardiothoracic surgery, and further research on this topic may be considered to implement this innovative tool in daily clinical practice. Lay summary Over the past decades, surgery on the heart and vessels is becoming more and more complex, necessitating more precise and accurate preoperative planning. Nowadays, operative planning is feasible on flat, two-dimensional computer screens, however, requiring a lot of spatial and three-dimensional (3D) thinking of the surgeon. Since immersive 3D virtual reality (VR) is an upcoming imaging technique with promising results in other fields of surgery, we aimed in this study to explore the additional value of this technique in heart surgery. Our surgeons planned six different heart operations by visualizing computed tomography scans with a dedicated VR headset, enabling them to visualize the patient’s anatomy in an immersive and 3D environment. The outcomes of this preliminary study are positive, with a much more reality-like simulation for the surgeon. In such, VR could potentially be beneficial as a preoperative planning tool for complex heart surgery.

scholarly journals How Can I Grab That?

i-com ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 67-85
Author(s):  
Matthias Weise ◽  
Raphael Zender ◽  
Ulrike Lucke
Keyword(s):  
Virtual Reality ◽  
User Experience ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Advantages And Disadvantages ◽  
Multiple Dimensions ◽  
Application Developers ◽  
Three Dimensional Space

AbstractThe selection and manipulation of objects in Virtual Reality face application developers with a substantial challenge as they need to ensure a seamless interaction in three-dimensional space. Assessing the advantages and disadvantages of selection and manipulation techniques in specific scenarios and regarding usability and user experience is a mandatory task to find suitable forms of interaction. In this article, we take a look at the most common issues arising in the interaction with objects in VR. We present a taxonomy allowing the classification of techniques regarding multiple dimensions. The issues are then associated with these dimensions. Furthermore, we analyze the results of a study comparing multiple selection techniques and present a tool allowing developers of VR applications to search for appropriate selection and manipulation techniques and to get scenario dependent suggestions based on the data of the executed study.

A New Geometric Model of Laid-in Weft-Knitted Fabrics

2021 ◽  
pp. 004051752199276
Author(s):  
Ki Wai Fong ◽  
Si Qing Li ◽  
Rong Liu
Keyword(s):  
Cost Estimation ◽  
Geometric Model ◽  
Three Dimensional ◽  
Wearable Electronics ◽  
Material Consumption ◽  
Knitted Fabrics ◽  
Functional Textiles ◽  
Loop Pattern ◽  
Spatial Configurations ◽  
Consumption Prediction

Inlay yarn and laid-in structures are important technical knitting elements that have been increasingly applied in the structural design of functional textiles in industrial, medical, and wearable electronics fields. However, there is no currently established geometric model to numerically analyze their spatial morphologies and structural properties. This study presents a new geometric model and numerical analysis approach to characterize spatial configurations of inlay yarn and ground yarn in a three-dimensional scenario for laid-in weft-knitted fabrics. Loop lengths of the inlay and ground yarn materials were calculated and analyzed under different contact and deformation conditions to estimate material consumption in this complex interlooping layout. Series of laid-in weft-knitted fabrics made of different combinations of ground and inlay yarns were fabricated with the 1 × 1 laid-in loop pattern and tested for the model validation. The comparisons between the experimental and calculated results indicated that the newly developed geometric model favorably agreed with the experimental measurements regarding the ground loop lengths and inlay loop lengths applied in the laid-in weft-knitted structures. The results indicated the applicability of the developed geometric model of laid-in weft-knitted fabrics with similar structural patterns in practical use. The output of this study provides a theoretical and practical reference for structural and physical properties analysis, material consumption prediction, even cost estimation of laid-in weft-knitted fabrics.

scholarly journals Simulation and Analysis of Floodlighting Based on 3D Computer Graphics

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1042
Author(s):  
Rafał Krupiński
Keyword(s):  
Computer Graphics ◽  
External Surface ◽  
Geometric Model ◽  
Three Dimensional ◽  
Fold Increase ◽  
Luminance Level ◽  
Object Model ◽  
Geometric Mesh ◽  
Average Luminance ◽  
To Receive

The paper presents the opportunities to apply computer graphics in an object floodlighting design process and in an analysis of object illumination. The course of object floodlighting design has been defined based on a virtual three-dimensional geometric model. The problems related to carrying out the analysis of lighting, calculating the average illuminance, luminance levels and determining the illuminated object surface area are also described. These parameters are directly tied with the calculations of the Floodlighting Utilisation Factor, and therefore, with the energy efficiency of the design as well as the aspects of light pollution of the natural environment. The paper shows how high an impact of the geometric model of the object has on the accuracy of photometric calculations. Very often the model contains the components that should not be taken into account in the photometric calculations. The research on what influence the purity of the geometric mesh of the illuminated object has on the obtained results is presented. It shows that the errors can be significant, but it is possible to optimise the 3D object model appropriately in order to receive the precise results. For the example object presented in this paper, removing the planes that do not constitute its external surface has caused a two-fold increase in the average illuminance and average luminance. This is dangerous because a designer who wants to achieve a specific average luminance level in their design without optimizing the model will obtain the luminance values that will actually be much higher.

Lucid Mapping: Information Landscaping and Three-Dimensional Writing Spaces

Leonardo ◽  
1999 ◽  
Vol 32 (4) ◽  
pp. 261-268 ◽  
Author(s):  
Matthew Kirschenbaum
Keyword(s):  
Virtual Reality ◽  
Three Dimensional ◽  
Visual Language ◽  
Modeling Language ◽  
Interactive Graphics ◽  
Rhetorical Strategies ◽  
Digital Arts ◽  
Virtual Reality Modeling Language ◽  
Electronic Environments ◽  
Mapping Information

This paper documents an interactive graphics installation entitled Lucid Mapping and Codex Transformissions in the Z-Buffer. Lucid Mapping uses the Virtual Reality Modeling Language to explore textual and narrative possibilities within three-dimensional (3D) electronic environments. The author describes the creative rationale and technical design of the work and places it within the context of other applications of 3D text and typography in the digital arts and the scientific visualization communities. The author also considers the implications of 3D textual environments on visual language and communication, and discriminates among a range of different visual/ rhetorical strategies that such environments can sustain.

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