共查询到20条相似文献,搜索用时 109 毫秒
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利用图形硬件的纹理映射和可编程GPU功能,高效实现基于焦点区域的体绘制.使用模板缓存检测机制把体数据标记为3个不同的区域,然后对标记区域使用基于纹理映射的方法分别绘制;同时使用基于GPU方法实现了周围区域的体轮廓绘制以及体绘制中多个转换函数的指定过程.文中方法使得体绘制系统实现容易、可扩展性好. 相似文献
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基于两步法的交互式纹理映射研究 总被引:1,自引:0,他引:1
两步纹理映射方法将映射过程分解为S映射与O映射两步进行.针对两步纹理映射方法研究中复杂物体表面纹理映射时出现的变形问题,采用B样条曲面代替简单的中间映射媒介,用它近似地包裹在三维物体的外表面,将纹理通过某种方式映射到曲面上实现参数化.基于两步映射方法提出了一种交互式纹理映射的算法.该算法允许用户交互选择贴图范围,通过控制B样条曲面实现对映射效果的调整.实验结果表明,该算法可显著提高纹理映射质量,纹理贴图效果良好. 相似文献
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基于深度纹理的实时碰撞检测算法 总被引:1,自引:0,他引:1
结合层次包围盒和基于图形硬件的方法,以带深度纹理的包围盒替代物体的几何模型,利用图形硬件在纹理映射时进行深度比较,以实现碰撞检测.实验结果表明,与CULLIDE算法相比,文中算法执行效率更高且执行时间固定,具有较高的实时性. 相似文献
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为更好地实现对三维模型局部细节的描写,提出一种中心扩散局部区域纹理映射方法.该方法以初始种子面为中心,采用广度优先搜索方法扩散确定待映射区域,保证待映射区域获得更好的圆度.在实现根据初始种子面的位置变化改变映射区域位置的同时,可始终保证纹理图像中心与纹理映射区域中心的对应,避免了纹理图像中心在纹理映射区域的中心偏移问题.实验结果表明了该方法的可行性. 相似文献
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硬件加速的等值面提取与绘制 总被引:1,自引:0,他引:1
图形硬件的发展为通用计算提供了新的平台.利用图形硬件的高密集和并行运算能力,将非规则四面体网格数据映射为纹理,在GPU中从每个四面体提取等值面片,并将其绘制到纹理而得到最终等值面.基于Cg着色器编程语言实现三维雷达作用范围表现的实验结果表明:该方法有效的减轻了CPU负担,提高了等值面提取速度,适于实时应用. 相似文献
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针对由VRML构造的虚拟实体造型表面进行跨区域纹理映射所遇到的困难,利用分而治之的思想,提出了一种比较简单有效的多曲面纹理映射的方法,实现了虚拟实体具有根据用户要求动态改变实体表面纹理的功能,在实现区域分割的同时也使多曲面纹理映射更加容易实现. 相似文献
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对物体进行纹理贴图的主要方法是将纹理坐标同物体表面顶点坐标建立关联,但是在建模软件之外由于没有物体的顶点坐标信息,要实现纹理映射相当困难.在OSG的基础上,采用重构规则物体表面的方法实现了物体的按面纹理映射,并得到了预期的效果. 相似文献
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传统的Java程序利用软件Java虚拟机(Java Virtual Machine,JVM)对Java字节码文件进行解释或二次编译后交由本地CPU执行,其运行速度大大受限,而硬件JVM处理器可直接执行Java字节码,因而大幅提高了Java程序的运行速度,所以硬件JVM处理器是突破Java程序性能瓶颈的最有效方法.本文以Jop Java及picoJava为例,根据Java虚拟机的规范分析了硬件JVM处理器中最重要的流水线结构、堆栈结构及操作的实现方式、指令折叠技术和字节码与微码的映射技术,并提出了改进措施. 相似文献
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《Graphical Models》2000,62(6):391-410
While 2D texture mapping is one of the most effective of the rendering techniques that make 3D objects appear visually interesting, it often suffers from visual artifacts produced when 2D image patterns are wrapped onto the surfaces of objects with arbitrary shapes. On the other hand, 3D texture mapping generates highly natural visual effects in which objects appear carved from lumps of materials rather than laminated with thin sheets as in 2D texture mapping. Storing 3D texture images in a table for fast mapping computations, instead of evaluating procedures on the fly, however, has been considered impractical due to the extremely high memory requirement. In this paper, we present a new effective method for 3D texture mapping designed for real-time rendering of polygonal models. Our scheme attempts to resolve the potential texture memory problem by compressing 3D textures using a wavelet-based encoding method. The experimental results on various nontrivial 3D textures and polygonal models show that high compression rates are achieved with few visual artifacts in the rendered images and a small impact on rendering time. The simplicity of our compression-based scheme will make it easy to implement practical 3D texture mapping in software/hardware rendering systems including real-time 3D graphics APIs such as OpenGL and Direct3D. 相似文献
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为了解决在标准PC机上对大数据进行实时体绘制的问题,提出了一种基于图形处理器的大数据高质量体绘制算法。该算法采用三维纹理映射作为核心的绘制算法,结合可见性测试、遮挡测试和模板测试来加快绘制速度。实验结果表明,对虚拟人体数据,可以在不损失图像质量的前提下,以可交互的速度进行绘制。 相似文献
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基于OpenGL标准库的复合纹理贴图方法 总被引:2,自引:0,他引:2
卢曼莎 《计算机工程与设计》2006,27(8):1505-1508
当前,多数三维图形设计软件都具有纹理映射功能,但对多幅纹理的复合贴图功能支持不够,不能很好地满足用户的需要.在保证可移植性,即不使用OpenGL多重纹理扩展的前提下,提出基于OpenGL标准库的复合纹理贴图方法,用户能够用本方法实现两幅纹理按照二值掩膜图进行纹理复合,生成新纹理,并可方便地使用参数设置来控制纹理效果. 相似文献
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Carlos A. Jara Francisco Esquembre Wolfgang Christian Francisco A. Candelas Fernando Torres Sebastián Dormido 《Computer Physics Communications》2012,183(2):231-244
Computer modeling is a powerful instructional tool which can be used to engage students in the design of physical models to describe, explain, and predict physics phenomena. Because implementing a model is difficult for researchers and teachers as well as for students, professionals almost always use discipline-specific code libraries to access a needed functionality in a platform independent manner. For example, although three-dimensional (3D) visualization is of great importance when displaying computer-generated data or showing complex motion, few users are prepared to deal with hardware accelerated video cards to graphically display a visualization. This paper describes a Java-based 3D framework which is based on physics principles. Our framework is defined using abstract Java interfaces that are implemented in the Open Source Physics (OSP) code library. The library contains a Simple 3D implementation that uses only the standard Java distribution and will run on any Java-enabled computer. This paper introduces a new implementation that makes use of Java 3D to improve both the performance and the appearance of implemented models. Examples are presented using both pure Java code and the Easy Java Simulations authoring tool and these examples are available through the ComPADRE OSP digital library. 相似文献
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Texture mapping has been widely used to improve the quality of 3D rendered images. To reduce the storage and bandwidth impact
of texture mapping, compression systems are commonly used. To further increase the quality of the rendered images, texture
filtering is also often adopted. These two techniques are generally considered to be independent. First, a decompression step
is executed to gather texture samples, which is then followed by a separate filtering step. We have investigated a system
based on linear transforms that merges both phases together. This allows more efficient decompression and filtering at higher
compression ratios. This paper formally presents our approach for any linear transformation, how the commonly used discrete
cosine transform can be adapted to this new approach, and how this method can be implemented in real time on current-generation
graphics cards using shaders. Through reuse of the existing hardware filtering, fast magnification and minification filtering
is achieved. Our implementation provides fully anisotropically filtered samples four to six times faster than an implementation
using two separate phases for decompression and filtering. Additionally, our transform-based compression also provides increased
and variable compression ratios over standard hardware compression systems at a comparable or better quality level. 相似文献
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为了给医生提供一些全面、直观和准确的诊断信息 ,讨论了一种对医学图象体数据场进行二维和三维剖切显示的方法 ,其中对于二维剖切显示 ,可首先由用户通过人机交互的方式来给出对体数据场进行任意剖切显示的路径 ;然后运用反求工程的求解思路沿切割路径进行量化和采样来得到沿切割路径上每个采样点在对应图象坐标空间中的位置 ,并由此获得剖切平面上所有采样点的空间位置坐标 ;最后通过对体数据场进行重采样和插值操作来实现对空间体数据场的二维任意剖切显示 .对于三维剖切显示 ,可首先采用与二维剖切操作类似的图象采样和插值操作来获得纹理数据阵列 ,然后结合纹理映射技术 ,将纹理数据映射到三维坐标空间中 ,以实现数据场的三维空间剖切显示 相似文献