GB/T 36341.4-2018Information technology—Information presentation of shape modeling—Part 4: Storage format (English PDF)

3.1 Shape group

A combination of a continuous representation of a form and a discrete representation of a form.

3.2 Shape model

A general term for shape modeling information.

4.1 Overview

This part adopts a tree-shaped storage structure in the form of organization. This structure contains all the objects in the system and their parent-child relationship. System, and defines the storage format of the node.

4.2 Tree Storage Structure

The tree storage structure defined in this section is shown in Figure 1.

4.3 Node storage structure

This section defines a node storage structure, all the shape models in GB/T 36341.1 and GB/T 36341.2 are as follows The storage format is stored in the node.

An object is a collection of name/value pairs starting with a "{" (left brace) tag and ending with a "}" (right brace) tag. Name passed The "identifier" of the object or object attribute is stored, followed by a "." (colon) and its "value", and multiple "name/value" pairs with "," (comic No.) interval, as shown in Figure 2.

The type of "value" in the object storage format can be the object itself, or it can be a single value or an array.

The array begins with "< " (left angle bracket) and ends with ">" (right angle bracket), with each value in the array separated by "," (comma). As shown in Figure 3.

Numeric types include. INT type, REAL type, string type, bool type, and SEM type.

The INT type is an integer type, the REAL type is a float type, the string type is a string type, and the bool type is a boolean type. SEM class The type is a user-defined data type, which can be composed of the above basic data types.

This part uses the global index, which is the unique identifier of the shape model. The identifier is id, starting from 1.

5.1 Continuous representation of the body

5.1.1 Points

The identifier of the point is Point. The attribute description of Point is shown in Table 1.

5.1.2 Basic curve

5.1.2.1 Straight line

The identifier of the line is Line. The properties of the line are described in Table 2.

5.1.2.2 Straight line segment

The identifier of the line segment is LineSegment. The properties of the line segment (LineSegment) are shown in Table 3.

5.1.2.3 Circle

The identifier of the circle is Circle. The attributes of the Circle are described in Table 4.

5.1.2.4 Arc

The identifier of the arc is Arc. The properties of the arc (Arc) are described in Table 5.

5.1.2.5 Ellipse

The identifier of the ellipse is Elipse. The attributes of the ellipse (Elipse) are shown in Table 6.

5.1.3 Basic surface

5.1.3.1 Plane

The identifier of the plane is Plane. The properties of the Plane are shown in Table 7.

5.1.3.2 Cylindrical surface

The identifier of the cylindrical surface is CylindricalSurface. The properties of the cylindrical surface (CylindricalSurface) are shown in Table 8.

5.1.3.3 Conical surface

The identifier of the conical surface is ConicalSurface. The properties of the ConicalSurface are described in Table 9.

5.1.3.4 Spherical

The identifier for the sphere is Sphere. The properties of the sphere (Sphere) are described in Table 10.

5.1.3.5 Ellipsoid

The identifier of the ellipsoid is Elipsoid. The properties of the ellipsoid (Elipsoid) are shown in Table 11.

5.1.3.6 Torus

The identifier of the torus is Toroid. The properties of the Toroid are shown in Table 12.

5.1.3.7 Positive prism face

The identifier of the positive prism face is PrismaticSurface. The properties of the Prismatic Surface are shown in Table 13.

5.1.3.8 Positive pyramid surface

The identifier of the regular pyramid is PyramidSurface. The properties of the Pyramid Surface are shown in Table 14.

5.1.4 Basic Geometry

5.1.4.1 Cuboid

The identifier of the cuboid is Cuboid. The properties of the Cuboid are shown in Table 15.

5.1.4.2 Cylinder

The identifier of the cylinder is Cylinder. The properties of the cylinder are shown in Table 16.

5.1.4.3 Cone

The identifier of the cone is Cone. The properties of the cone are as shown in Table 17.

5.1.4.4 Sphere

The identifier of the sphere is Spherome. The properties of the sphere (Spherome) are shown in Table 18.

5.1.4.5 Positive pyramid

The identifier of the positive pyramid is RegularPyramid. The properties of the regular pyramid (RegularPyramid) are shown in Table 19. […]