In order to further enrich the form of 3D Mandelbrot and Julia sets, this paper first presents two methods of generating 3D fractal sets by utilizing discrete modifications of the standard quaternion algebra and analy...In order to further enrich the form of 3D Mandelbrot and Julia sets, this paper first presents two methods of generating 3D fractal sets by utilizing discrete modifications of the standard quaternion algebra and analyzes the limitations in them. To overcome these limitations, a novel method for generating 3D fractal sets based on a 3D number system named ternary algebra is proposed. Both theoretical analyses and experimental results demonstrate that the ternary-algebra-based method is superior to any one of the quad-algebra-based methods, including the first two methods presented in this paper, because it is more intuitive, less time consuming and can completely control the geometric structure of the resulting sets. A ray-casting algorithm based on period checking is developed with the goal of obtaining high-quality fractal images and is used to render all the fractal sets generated in our experiments. It is hoped that the investigations conducted in this paper would result in new perspectives for the generalization of 3D Mandelbrot and Julia sets and for the generation of other deterministic 3D fractals as well.展开更多
This paper introduces the techniques of direct volume rendering in VTK and discusses ray-casting--the most popular technique of direct volume rendering. The visualizations for medical volumetric data by three function...This paper introduces the techniques of direct volume rendering in VTK and discusses ray-casting--the most popular technique of direct volume rendering. The visualizations for medical volumetric data by three functions of raycasting are offered. Visualization effects prove that VTK is easy to get satisfied resuits with good quality in short time.展开更多
Ray-casting technique used to generate realism graphs is creatively applied to simulate the NC machining process of an integral turbo-wheel, thus the representation of a workpiece is redused from 3D to 1D. As a result...Ray-casting technique used to generate realism graphs is creatively applied to simulate the NC machining process of an integral turbo-wheel, thus the representation of a workpiece is redused from 3D to 1D. As a result, simulation speed is raised greatly and the visualization is kept. The relative problems are the discussed in detail and the 5 - axis NC machining process simulation of integral turbo-wheel is illustrated with Ray-casting representation.展开更多
A holographic visualization of volume data based on adjustable ray to optical-wave conversion is presented.Computergenerated holograms are generated by emitting multiple rays to sample the volumetric field.Equal inter...A holographic visualization of volume data based on adjustable ray to optical-wave conversion is presented.Computergenerated holograms are generated by emitting multiple rays to sample the volumetric field.Equal interval sampling,object light wave adjustment,and information composition are sequentially performed during the march of rays.The program is accelerated in parallel to reduce the total time,and the reconstructions are dynamically adjusted to express different parts of an object.Optical experiments verify that the proposed method can holographically reconstruct the surface and interior information of objects.展开更多
基金Project supported by the National Basic Research Program (973) of China (Nos. 2004CB719402 and 2002CB312106), the National Natural Science Foundation of China (Nos. 60375020 and 50305033), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20020335112)
文摘In order to further enrich the form of 3D Mandelbrot and Julia sets, this paper first presents two methods of generating 3D fractal sets by utilizing discrete modifications of the standard quaternion algebra and analyzes the limitations in them. To overcome these limitations, a novel method for generating 3D fractal sets based on a 3D number system named ternary algebra is proposed. Both theoretical analyses and experimental results demonstrate that the ternary-algebra-based method is superior to any one of the quad-algebra-based methods, including the first two methods presented in this paper, because it is more intuitive, less time consuming and can completely control the geometric structure of the resulting sets. A ray-casting algorithm based on period checking is developed with the goal of obtaining high-quality fractal images and is used to render all the fractal sets generated in our experiments. It is hoped that the investigations conducted in this paper would result in new perspectives for the generalization of 3D Mandelbrot and Julia sets and for the generation of other deterministic 3D fractals as well.
基金The author gratefully acknowledges the support of Youth for NWPUTeachers Scientific and Technological Innovation Foundation (5210102-0800-M016206)This work is supported by a grant for PH.D Site from Chinese Educational Department (20040699015)The authors are thankful to Guiqing He, PhD and Chongyang Hao, professor for many help and interesting discussions.
文摘This paper introduces the techniques of direct volume rendering in VTK and discusses ray-casting--the most popular technique of direct volume rendering. The visualizations for medical volumetric data by three functions of raycasting are offered. Visualization effects prove that VTK is easy to get satisfied resuits with good quality in short time.
文摘Ray-casting technique used to generate realism graphs is creatively applied to simulate the NC machining process of an integral turbo-wheel, thus the representation of a workpiece is redused from 3D to 1D. As a result, simulation speed is raised greatly and the visualization is kept. The relative problems are the discussed in detail and the 5 - axis NC machining process simulation of integral turbo-wheel is illustrated with Ray-casting representation.
基金partly supported by the National Natural Science Foundation of China (Nos. 61905017 and 61905019)the Fundamental Research Funds for the Central Universities (Nos. 2019RC13 and 2019PTB-018)
文摘A holographic visualization of volume data based on adjustable ray to optical-wave conversion is presented.Computergenerated holograms are generated by emitting multiple rays to sample the volumetric field.Equal interval sampling,object light wave adjustment,and information composition are sequentially performed during the march of rays.The program is accelerated in parallel to reduce the total time,and the reconstructions are dynamically adjusted to express different parts of an object.Optical experiments verify that the proposed method can holographically reconstruct the surface and interior information of objects.
