查询词典 3D

This paper introduces the software structure and real time process principle of real time NC system, according to the milling process character of NC system and the geometrical modeling method of computer simulation, presents a technique of subdividing roughcasts and data structures which applies to the computer simulation of the NC milling process; and in order to quicken the operating rate and enhance the reality of computer simulation, puts forward a logic algorithm of the 3D milling process of real time NC system which can display the effects of the computer simulation of 3D milling process of real time NC system dynamicly and efficiently in PC, such as the movement of tools, the elimination of materials, the shape changing of roughcasts.

刘景能，蒙艳玫（广西大学，530004）摘要：本文介绍了实时数控系统软件结构与实时工作原理，根据数控系统铣削加工的特点和计算机仿真几何建模方法，给出了适用于数控铣削加工仿真的毛坯离散细分方法和数据结构；为了加快处理速度和增强仿真效果真实感，提出了一种实时数控系统三维加工仿真的逻辑设计算法，即在单CPU机器单线程程序中使用普通软件循环和定时器模拟实现多线程，该算法可以在微机上动态显示高质量的铣削加工过程刀具的运动，材料的去除和毛坯形状的变化等数控加工三维仿真效果。

Traditionally, a surface is usually scatted in an array of 3D data points which are topologically connected by rows and columns to form a rectangular mesh. This method can't meet the requirement of description and measurement for some complex surfaces. On the basis of tracing border points, a new method is proposed to deliver 3D data points of surfaces, which are topologically constructed with optimum rectangular and triangular mesh. In order to measure surface efficiently and safely with NC machine, an optimization of measurement paths is proposed to avoid interference between the measuring tool and the surface with holes. The curve design is the basis of surface modeling.

数控测量技术的发展为测量自动化、集成化、智能化提供了可能，而对于复杂曲面的自动测量规划则是测量技术中的难点问题，平行截面等数目测点分布和四边拓扑测点分布规划方法，不论在测点分布的合理性上还是在网格结构的优化方面，均难以满足形状或边界较复杂曲面的离散化描述和曲面造型的要求，为了实现任意拓扑曲面的自动测量，本文对复杂曲面的合理离散化描述和自动测量问题进行了研究，提出了基于边界跟踪、优化网格的测点自动分布规划和四边、三角混合网格的生成方法：同时对具有孔洞或测量干涉凸台等非完整曲面的测量路径优化问题进行了研究，提出了路径优化方法。

3D-CTM (Coupled Thermo-Mechanical Forming Simulation) software for precision forging process of aero-engine blade was developed. The key technologies of 3D coupled rigid-viscoplastic thermo-mechanical FEM simulation of blade forging process were studied systematically. By using the remeshing method of contracting from the boundary to the inner, new mesh system from old distorted mesh system can be obtained. A method of modifying the position of nodes touching on the die according to its original normal was proposed to avoid "dead lock" problem due to uncontinuity of normal of scatted die meshes. The pseudo-static iterative algorithm was used to simplify the coupled thermo-mechanical computation. In particular, formulations to determine relaxation factor β was established for rigid viscoplastic FEM adopting penalty function method, and an improved cubic factor rapid algorithm derived from these formulations was proposed by combining with the advantage of advance and retreat search method.

采用基于边界构形的内缩法，实现了三维畸变网格的重新划分；提出了初矢修正法对触模节点的位置进行修正，解决了由于离散的模具网格的法矢不连续造成的&死锁&问题；采用准静态迭代法简化了速度场和温度场耦合计算过程；特别是针对减速因子β的选取，建立了适用于三维复杂成形过程刚粘塑性罚函数法有限元三次因子法的计算公式，并结合进退搜索法提出了改进的三次因子快速算法，提高了模拟计算效率和稳定性，在此基础之上，开发了面向叶片精锻过程的三维刚粘塑性热力耦合有限元模拟分析系统(3D-CTM)，系统的可靠性得到了圆柱体镦粗的验证。

Part II shows how to implement elementary 3D techniques, such as defining 3D geometry, lighting, texturing, alpha blending, and stenciling, using shaders and the HLSL.

第二部分将引导读者学会实现基本的3D 技术如用渲染和 HLSL 定义三维几何，光照，纹理等等。

Point cloud. Proposed a multi-mesh based inverse kinematics; Developed a fast trapeziums based method for shadow volumes to improvethe reality of resulting 3D animation; Implemented the above methods to develop a new integrated 3D animatingprototype system.The dissertation is organized as follows.

提出了基于样例的交互式三维动画生成方法√为了加强动画的真实感，提出了基于梯形的阴影锥快速产生算法；√最重要的贡献，即通过组和这些不同的算法，提出了一个基于样例的完整的动画制作系统——ABE原型系统。

It is simple, fast and precise to measure objects three dimensionally through structured light. It is also fast and exact to reconstruct the 3D shape of object by triangulating the 3D data points.

利用结构光可以简单、快速并且精确地对被测物体进行三维测量，对获取的三维数据点集进行三角剖分，可以快速准确地重建被测物体的三维形状。

When the 3D model is rendered, the texture image is "wallpapered" onto the geometry of the 3D model.

当3D模型动画变化或被改变形状，纹理图元仍然保持在模型上。

A digital 3D presentation that wows viewers with striking 3D effects, Fly Me to the Moon is a retelling of the 1969 Apollo 11 landing on the moon from the perspective of three young flies that allegedly hitched a ride on the historic flight.

数字三维演示文稿，让观众拍案叫绝惊人的3D效果，彩云追月月球是一个年轻的复述了1969年阿波罗11登陆三个角度对月球的苍蝇据称顺风车历史性飞行一坐。

The term z-map might be a little misleading to those who are not familiar to working in 3D space. In high school geometry class the concept of two-dimensional space: the x-axis represents horizontal space and the y-axis represents vertical space. Whenever you work in packages such as Painter, Photoshop, Commotion, Combustion or After Effects you are working solely in 2-dimensional space. When you work in 3D you have, in addition to the x- and y-axes, a z-axis, representing depth.

z-map这个称呼或许对那些不从事三维空间工作的人来说有一点误导的嫌疑，在高校的几何课里面，关于二维空间的概念，X轴代表着横向空间，而Y轴代表着纵向空间，无论何时你使用例如Painter， Photoshop， Commotion， Combustion 或After Effects这样的软件，你正工作在一个二维的空间，但是在三维空间工作时，除了X轴和Y周，你还要加上Z轴，它代表了深度的概念。

Based on the 3D time-average Navier-Stokes equations, k-ε model was used to simulate the 3D turbulent flow field of whole flow passage in the Francis turbine including guide wickets, runner and draft tube. The energy performance and cavitation performance were predicted from the simulation results, and the calculated data were compared with the results of hydraulic turbine model experiment. The calculation of turbine efficiency and the measured efficiency was very closed and the maximal relative error was 0.9%.

该文基于Navier-Stokes方程和k-ε紊流模型，采用贴体坐标和交错网格系统，用SIMPLEC算法对一模型混流式水轮机引水元件、转轮和尾水管进行了联合计算与转轮单流道计算，数值模拟了水轮机各通流元件内部三维湍流流场，预测了水轮机的能量性能和空化性能，并与水轮机模型试验结果进行了对比。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。