Three dimensional Boolean calculating method for quantity survey in construction

Abstract

The invention discloses a three dimensional Boolean calculating method for quantity survey in construction. First, a subtraction relational expression of members to be calculated is analyzed according to civil engineering calculating rules. Then, for each correlation members in the subtraction relational expression, all segmentation lines between original geometric bodies are calculated according to intersection and overlapping relation of the original geometric bodies; each original geometric body is cut one time according to the segmentation lines, all the facets of the cut geometric bodes are analyzed to obtain the positional relation of the facets relative to the original geometric bodies of the correlation members; the corresponding geometric bodies are calculated by collecting the facets according to the positional relation of facets; and at last, the parameters of the corresponding geometric bodies are analyzed and are substituted in the corresponding formula used for calculating geometrical quantity to obtain geometrical quantity of corresponding geometric bodies. The three dimensional Boolean calculating method for quantity survey in construction improves stability and calculating speed, and can in real time render three dimensional geometric bodies obtained by calculating.

Description

technical field [0001] The invention relates to the field of building calculations, in particular to a three-dimensional Boolean calculation method used in the field of building calculations. Background technique [0002] The commonly used representation of 3D geometry is described by surface fragments. The area enclosed by the surface separates the geometry from the external space, and the inside of the area is the interior of the geometry. The following summarizes common surface representation methods [0003] 1) Parametric equations. For example, the radius is R, and the coordinates of the center of the circle (X 0 , Y 0 ,Z 0 ) The parametric equation of the sphere surface is [0004] (x-x 0 ) 2 +(y-y 0 ) 2 +(z-z 0 ) 2 =R 2 [0005] 2) Polygon patch representation. Divide the geometric surface into non-coplanar polygons, record the vertex position coordinates of each polygon, the topological relationship of edges and the index number of the corresponding ve...

AI Technical Summary

Problems solved by technology

The defect of this method is similar to 1). Its data structure does not adapt to the data structure of the current graphics card. It needs to be calculated and re-triangulated. The conversion process is extremely slow, so it is not practical

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