一种大规模体数据压缩体绘制策略

针对基于GPU的大规模体数据直接体绘制过程中遇到的显存不足的问题，提出了一种大规模体数据的压缩绘制策略.该策略结合小波变换和分类矢量量化进行数据压缩，采用基于GPU的光线投射算法进行绘制，在绘制时，只解压变换当前绘制所需要的极少数数据，并结合多分辨率绘制，实现实时交互.基于CUDA的实验表明：该压缩绘制策略有效解决了显存不足问题，并且在保证交互绘制帧率的前提下获得了较好的成像质量.     

基于云计算技术和3D渲染的农机虚拟制造技术研究

为了提高农机现代化和批量化生产效率,实现基于个性化需求农机设计和制造,提出了面向机加工的云技术农机制造服务候选资源的发现方法,并设计了农机虚拟制造的云计算平台。在农机部件云制造虚拟平台中,首先利用云存储技术存放大量的候选制造企业资源样本数据,然后利用智能分类算法KNN对候选资源进行分类,根据农机部件制造需求的客户对候选资源进行优选,最后得到最佳的候选资源。基于云计算和3D渲染技术,构建了面向工序级和零件级服务的仿真环境,并通过仿真实验,得到了优选后服务方的服务时间、费用和合格率,为现代农机的批量生产和个性化加工服务提供了新的解决方案。     

THREE-DIMENSIONAL MULTISLICE HELICAL COMPUTED TOMOGRAPHY TECHNIQUES FOR CANINE EXTRA-HEPATIC PORTOSYSTEMIC SHUNT ASSESSMENT

The purpose of the present study was to investigate the feasibility and usefulness of three-dimensional (3D) multislice computed tomography (CT) angiography with maximum intensity projection (MIP) and volume rendering (VR) in six dogs with clinical and sonographic findings suggestive of portosystemic shunt. Furthermore, we aimed to estimate the diameter of the portal vein and shunt vessels. MIP and VR reconstructions were performed for each patient and the origin and insertion of all shunt vessels were detected. In addition, 3D reconstructions allowed excellent depiction of vascular morphology and topography. All diagnoses and vessel measurements were confirmed by surgery. 3D multidetector CT angiography is a promising, noninvasive, and accurate method of evaluating dogs with suspected portosystemic shunts.     

秦汉时期官方蓄犬现象研究

秦汉时期,官方蓄犬非常普遍。按正史记载及律令要求,此种现象既是选择偏好,也是制度使然,从朝廷中央到地方郡县、边关烽燧莫不如此。与之相应的是官方也为之配备专门的馆舍和官员。对这些犬只的管理,秦汉律令从数量、饲养环境、体型大小等角度都有限制。它们满足了各级官府治理鼠患、祭祀驱邪、娱乐狩猎、警戒防盗、肉食供给等多方面的需要。另外,此时文武官员对皇帝常以"犬马"自称,这种现象或许也与官方蓄犬浸染有关。     

Realistic Simulation of Rice Plant

The existing research results of virtual modeling of rice plant, however, is far from perfect compared to that of other crops due to its complex structure and growth process. Techniques to visually simulate the architecture of rice plant and its growth process are presented based on the analysis of the morphological characteristics at different stages. Firstly, the simulations of geometrical shape, the bending status and the structural distortion of rice leaves are conducted. Then, by using an improved mode...     

基于笔划的农产品图像生成研究

基于笔划的农产品油画生成是非真实感生成中一个重要的研究方面,它模拟真实画家使用笔划的创作过程,以达到逼真的手绘作品的效果。本文以笔划的方向为线索将基于笔划的农产品油画生成技术分为两类进行研究,即基于图像梯度笔划生成和基于构造笔划生成,然后分别对这两类技术的发展和主要算法进行分析和讨论。最后进行总结,分析两类技术的特点,并对未来基于笔划的农产品油画生成的发展作一个展望。     

Research and Development a Visualization System for Medical CT Images

In order to develop a 3D visualization system for medical CT images which comply with DICOM standard, the authors study DICOM file format and methods of analyzing it, discuss the key technology of adjusting Windows Center/Windows Level of Medical CT images and 3D visualization methods, and describe the system's structure and approaches to implement every function module. Through developing 3D reconstruction software of medical CT images, surface rendering is compared with volume rendering.We succeed in implementing the visualization system for medical CT images which comply with DICOM standard. This system provides an intuitionistic way for diagnosing with medical images. The system is significant in clinical environment.     

植物叶片渲染方法研究进展

数字植物是农业信息学的重要研究方向,而植物建模是数字植物的主要内容。作为植物最重要的器官,叶片的真实渲染是植物真实建模研究的关键。为此,描述了近些年来植物叶片渲染与可视化研究状况,并对单一时刻植物叶片表观渲染方法与随时间动态变化的叶片表观渲染方法分别进行了详细的介绍,同时对这两方面未来发展趋势进行了初步的探讨。     

基于高显色性白光LED的博物馆照明系统设计

在详细分析博物馆照明要求的基础上,提出了一种基于白光LED光源的博物馆照明系统解决方案,并进一步实现了低色温、高显色性1W白光LED的光谱学设计．试验证明,该照明系统解决方案可以满足博物馆内对光比较敏感的参展物品的照明需要．     

表面矢量编码的查找表算法

针对体绘制计算中严重影响绘制速度的光照效果处理运算,提出了利用表面矢量编码为索引,构造光照效果计算查找表的规划方法.算法编码简单,数据运算中内存的开销小,运算速度快,实际应用效果良好.