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
The volumetric rendering of 3 D medical image data is very effective method for communication about radiological studies to clinicians. Algorithms that produce images with artifacts and inaccuracies are not clinically...The volumetric rendering of 3 D medical image data is very effective method for communication about radiological studies to clinicians. Algorithms that produce images with artifacts and inaccuracies are not clinically useful. This paper proposed a direct voxel projection algorithm to implement volumetric data rendering. Using this algorithm, arbitrary volume rotation, transparent and cutaway views are generated satisfactorily. Compared with the existing raytracing methods, it improves the projection image quality greatly. Some experimental results about real medical CT image data demonstrate the advantages and fidelity of the proposed algorithm.展开更多
The emergence of high performance 3D graphics cards has opened the way to PC clusters for high performance multi- display environment. In order to exploit the rendering ability of PC clusters, we should design appropr...The emergence of high performance 3D graphics cards has opened the way to PC clusters for high performance multi- display environment. In order to exploit the rendering ability of PC clusters, we should design appropriate parallel rendering algorithms and parallel graphics library interfaces. Due to the rapid development of Direct3D, we bring forward DPGL, the Direct3D9-based parallel graphics library in D3DPR parallel rendering system, which implements Direct3D9 interfaces to support existing Direct3D9 application parallelization with no modification. Based on the parallelism analysis of Direct3D9 rendering pipeline, we briefly introduce D3DPR parallel rendering system. DPGL is the fundamental component of D3DPR. After presenting DPGL three layers architecture, we discuss the rendering resource interception and management. Finally, we describe the design and implementation of DPGL in detail, including rendering command interception layer, rendering command interpretation layer and rendering resource parallelization layer.展开更多
Three-dimensional surfaces are typically modeled as implicit surfaces.However,direct rendering of implicit surfaces is not simple,especially when such surfaces contain finely detailed shapes.One approach is ray-castin...Three-dimensional surfaces are typically modeled as implicit surfaces.However,direct rendering of implicit surfaces is not simple,especially when such surfaces contain finely detailed shapes.One approach is ray-casting,where the field of the implicit surface is assumed to be piecewise polynomials defined on the grid of a rectangular domain.A critical issue for direct rendering based on ray-casting is the computational cost of finding intersections between surfaces and rays.In particular,ray-casting requires many function evaluations along each ray,severely slowing the rendering speed.In this paper,a method is proposed to achieve direct rendering of polynomial-based implicit surfaces in real-time by strategically narrowing the search range and designing the shader to exploit the structure of piecewise polynomials.In experiments,the proposed method achieved a high framerate performance for different test cases,with a speed-up factor ranging from 1.1 to 218.2.In addition,the proposed method demonstrated better efficiency with high cell resolution.In terms of memory consumption,the proposed method saved between 90.94%and 99.64%in different test cases.Generally,the proposed method became more memory-efficient as the cell resolution increased.展开更多
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.
基金Shanghai Science and Technology Devel-opment Fund(9944 190 2 7)
文摘The volumetric rendering of 3 D medical image data is very effective method for communication about radiological studies to clinicians. Algorithms that produce images with artifacts and inaccuracies are not clinically useful. This paper proposed a direct voxel projection algorithm to implement volumetric data rendering. Using this algorithm, arbitrary volume rotation, transparent and cutaway views are generated satisfactorily. Compared with the existing raytracing methods, it improves the projection image quality greatly. Some experimental results about real medical CT image data demonstrate the advantages and fidelity of the proposed algorithm.
基金This work was supported by National Basic Research Program of China (No.2002CB312105)Key National Natural Science Foundation of China Project on Digital Olympic Museum(No.60533080).
文摘The emergence of high performance 3D graphics cards has opened the way to PC clusters for high performance multi- display environment. In order to exploit the rendering ability of PC clusters, we should design appropriate parallel rendering algorithms and parallel graphics library interfaces. Due to the rapid development of Direct3D, we bring forward DPGL, the Direct3D9-based parallel graphics library in D3DPR parallel rendering system, which implements Direct3D9 interfaces to support existing Direct3D9 application parallelization with no modification. Based on the parallelism analysis of Direct3D9 rendering pipeline, we briefly introduce D3DPR parallel rendering system. DPGL is the fundamental component of D3DPR. After presenting DPGL three layers architecture, we discuss the rendering resource interception and management. Finally, we describe the design and implementation of DPGL in detail, including rendering command interception layer, rendering command interpretation layer and rendering resource parallelization layer.
基金supported by JSPS KAKENHI Grant Number 21K11928。
文摘Three-dimensional surfaces are typically modeled as implicit surfaces.However,direct rendering of implicit surfaces is not simple,especially when such surfaces contain finely detailed shapes.One approach is ray-casting,where the field of the implicit surface is assumed to be piecewise polynomials defined on the grid of a rectangular domain.A critical issue for direct rendering based on ray-casting is the computational cost of finding intersections between surfaces and rays.In particular,ray-casting requires many function evaluations along each ray,severely slowing the rendering speed.In this paper,a method is proposed to achieve direct rendering of polynomial-based implicit surfaces in real-time by strategically narrowing the search range and designing the shader to exploit the structure of piecewise polynomials.In experiments,the proposed method achieved a high framerate performance for different test cases,with a speed-up factor ranging from 1.1 to 218.2.In addition,the proposed method demonstrated better efficiency with high cell resolution.In terms of memory consumption,the proposed method saved between 90.94%and 99.64%in different test cases.Generally,the proposed method became more memory-efficient as the cell resolution increased.
