Thirdly,all global interfering ranges are detected by invoking a modified Choi&Park pair-wise interfering detection procedure,and global interfering ranges belonging to outloop and islands are deleted respectively;

A random array edge table is described as a basic data structure to form a plane chart, instead of the concepts about inner or outer rounding ring and point table.

This article describes an algorithm,i.e.two figures(composed of arcs and lines)are computed by union,intersection and difference to construct a new geometric figure.Also it describes the problem with window cllipping,both the window and the figure contains several inner loops and one outer loop. The algorithm,data structures and modelling techniques are introduced here. They have been used in the engineering graphics processing for die equipment CAD and have provided a new method for drawing assembly drawings...

This article describes an algorithm,i.e.two figures(composed of arcs and lines)are computed by union,intersection and difference to construct a new geometric figure.Also it describes the problem with window cllipping,both the window and the figure contains several inner loops and one outer loop. The algorithm,data structures and modelling techniques are introduced here. They have been used in the engineering graphics processing for die equipment CAD and have provided a new method for drawing assembly drawings by means of computers.

Each group of the arbitrary figure attending operation has been expandded into a number of elements. Each element has been expanded into inside ring, outside ring, and virtual ring. The relative positions of elements between each group of figures are devoloped into the combinations of 4 cases, such as intersection, seperation, containment and coincidence 5 operations of union, intersection, difference, extension and containment can be made, then, 8 results can be obtained. Former modele adopting the broken line...

Each group of the arbitrary figure attending operation has been expandded into a number of elements. Each element has been expanded into inside ring, outside ring, and virtual ring. The relative positions of elements between each group of figures are devoloped into the combinations of 4 cases, such as intersection, seperation, containment and coincidence 5 operations of union, intersection, difference, extension and containment can be made, then, 8 results can be obtained. Former modele adopting the broken line to approximate arc (curve) is fully changed, arc in here is used as a basic element to directly operate, and a series of problems of special attitudes which are given rise by arc have been solved. The problems of "queer coincide point"and"second queer coincide point", and "virtual ring" are put forward and solved. All work has Successfully realized to join with AutoCAD, therefore, it has the ability of interactive modification. The ready of practice has been gotten.

In this paper, we design a graphic data structure, which is suitable for describing common 2-D figure, detail drawings and assembly drawings. The concept of loop is used in this data structure. The algorithm of two loops (single loop) Boolean operation and the algorithm of the one-way bridge edge are presented. On the basis of the above algorithm, we achieve the algorithm of two graphs (many loops) Boolean operation. Also the special cases of Boolean operation are discussed.The graph algorithm provides a novel...

In this paper, we design a graphic data structure, which is suitable for describing common 2-D figure, detail drawings and assembly drawings. The concept of loop is used in this data structure. The algorithm of two loops (single loop) Boolean operation and the algorithm of the one-way bridge edge are presented. On the basis of the above algorithm, we achieve the algorithm of two graphs (many loops) Boolean operation. Also the special cases of Boolean operation are discussed.The graph algorithm provides a novel method for creating detail and assembly drawings, which must be expressed by many loops. The algorithm makes the processing easy, such as digging hole, merging in views , assembling among detail drawings.