ISO 10303-42:2003 工业自动化系统和综合 产品数据显示和交换 第42部分：一般综合方法：几何和拓扑显示.

标准编号：ISO 10303-42:2003

中文名称：工业自动化系统和综合 产品数据显示和交换 第42部分：一般综合方法：几何和拓扑显示.

英文名称：Industrial automation systems and integration — Product data representation and exchange — Part 42: Integrated generic resource: Geometric and topological representation

发布日期：2003-04

标准范围

ISO 10303-42:2003规定了产品形状的显式几何和拓扑表示的资源结构。范围由理想产品模型的显式表示的要求决定；公差和特征方面的隐式表示形式超出了范围。条款4中的几何形状和条款5中的拓扑结构可独立使用，并且还被条款6中的各种形式的几何形状模型广泛使用。此外，ISO 10303-42:2003规定了表示概念的专门化，其中表示的元素是几何的。以下内容属于几何图形架构的范围:点、向量、参数曲线和参数曲面的定义；具有内部参数化的有限体积定义；变换算子的定义；直接由其坐标值或根据现有曲线或曲面的参数定义的点；圆锥曲线和初等曲面的定义；在参数曲面上定义的曲线的定义；一般参数样条曲线、曲面和体积的定义；点、曲线和曲面副本的定义；偏移曲线和曲面的定义；相交曲线的定义。以下内容超出了ISO 10303-42:2003的范围:所有其他形式的程序定义的曲线和曲面；不具有参数形式表示的曲线和曲面；直纹面的任何形式的显式表示。注意，对于直纹面，几何形状关键取决于边界曲线的参数化和将两条曲线上的点对关联的方法。然而，具有B样条边界曲线的直纹面可以由B样条曲面实体精确地表示。

ISO 10303-42:2003 specifies the resource constructs for the explicit geometric and topological representation of the shape of a product. The scope is determined by the requirements for the explicit representation of an ideal product model; tolerances and implicit forms of representation in terms of features are out of scope. The geometry in clause 4 and the topology in clause 5 are available for use independently and are also extensively used by the various forms of geometric shape model in clause 6.In addition, ISO 10303-42:2003 specifies specialisations of the concepts of representation where the elements of representation are geometric.The following are within the scope of the geometry schema:

• definition of points, vectors, parametric curves and parametric surfaces;
• definition of finite volumes with internal parametrisation;
• definition of transformation operators;
• points defined directly by their coordinate values or in terms of the parameters of an existing curve or surface;
• definition of conic curves and elementary surfaces;
• definition of curves defined on a parametric surface;
• definition of general parametric spline curves, surfaces and volumes;
• definition of point, curve and surface replicas;
• definition of offset curves and surfaces;
• definition of intersection curves.

The following are outside the scope of ISO 10303-42:2003:

• all other forms of procedurally defined curves and surfaces;
• curves and surfaces which do not have a parametric form of representation;
• any form of explicit representation of a ruled surface.

NOTE For a ruled surface the geometry is critically dependent upon the parametrisation of the boundary curves and the method of associating pairs of points on the two curves. A ruled surface with B-spline boundary curves can however be exactly represented by the B-spline surface entity.

标准预览图