pythonocc 求一条直线与一个梯形的交点的横坐标

坐标系为ZOX坐标系，X轴为横轴，Y轴为竖轴。直线为平行于X轴的一条直线。梯形为以Z轴为对称轴的梯形。附上代码。

# -*- coding: utf-8 -*-
"""
Created on Mon Jul 13 09:58:09 2020

@author: zxl
"""

from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakePolygon, BRepBuilderAPI_MakeFace
from OCC.Core.gp import gp_Pnt, gp_Dir, gp_Pln
from OCC.Core.TopExp import TopExp_Explorer
from OCC.Core.TopAbs import TopAbs_EDGE
from OCC.Core.TopoDS import topods
from OCC.Core.Geom import Geom_Line
from OCC.Core.gp import gp
from OCC.Core.BRep import BRep_Tool
from OCC.Core.GeomAPI  import GeomAPI_ExtremaCurveCurve

p0 = gp_Pnt()
vnorm = gp_Dir(0, 1, 0) # 法向量，平行于Y轴的单位向量
aPlane = gp_Pln(p0, vnorm) #ZOX平面

bcd = 150 #梯形的下底边长
tcd = 50 #梯形的上底边长
ht = 50 #梯形的高
offset = 0
z_of_trapezoid = 0 #梯形的底边的Z的坐标

x0 = -0.5 * bcd + offset #梯形的左下角顶点的X坐标
x1 = 0.5 * bcd + offset #梯形的右下角顶点的X坐标
x2 = 0.5 * tcd + offset #梯形的右上角顶点的X坐标
x3 = -0.5 * tcd + offset #梯形的左上角顶点的X坐标
z0 = z_of_trapezoid # 梯形的下底的Z坐标
z1 = z_of_trapezoid + ht # 梯形的上底的Z坐标
aP1 = gp_Pnt(x0, 0.0, z0)
aP2 = gp_Pnt(x1, 0.0, z0)
aP3 = gp_Pnt(x2, 0.0, z1)
aP4 = gp_Pnt(x3, 0.0, z1)
aPolygon = BRepBuilderAPI_MakePolygon(aP1, aP2, aP3, aP4, True)
aTrapezoid = BRepBuilderAPI_MakeFace(aPlane, aPolygon.Wire()).Shape()

#梯形面，类型为TopoDS_Face

aLine = Geom_Line(gp_Pnt(0.0, 0.0, 25), gp.DX())  # 梯形的中位线
print("type of aLine: ", type(aLine))

anEdgeExplorer = TopExp_Explorer(aTrapezoid, TopAbs_EDGE)

start_pnts = []  #交点的X坐标的列表
while anEdgeExplorer.More(): # 有更多子形状去挖掘
    anEdge = topods.Edge(anEdgeExplorer.Current()) # 当前被探索到的子形状是哪一个
    #print("current edge: ", anEdge)
            
    aCurve = BRep_Tool.Curve(anEdge)[0]
    aFirst = BRep_Tool.Curve(anEdge)[1] # 这条边的起始点
    aLast = BRep_Tool.Curve(anEdge)[2]  # 这条边的终止点
    #print("type of aCurve: ", type(aCurve))
    #print("type of sec: ", type(sec), "sec: ", sec)
    aExtrema = GeomAPI_ExtremaCurveCurve(aLine, aCurve, -1e308, 1e308, aFirst, aLast) 

    #GeomAPI_ExtremaCurveCurve(C1, C2, U1min, U1max, U2min, U2max)

    #C1 为曲线1，C2为曲线2，U1min, U1max是曲线1的起始点和终止点，U2min, U2max是曲线2的起始点和终止点，

    # 这里因为C1是一条无限长的直线，所以是-1e308, 1e308。而C2的起始点和终止点是由BRep_Tool.Curve(anEdge)[1]和#BRep_Tool.Curve(anEdge)[2]得到
    #print(type(aExtrema))
    print("number of aExtrema: ", aExtrema.NbExtrema())
    print("aExtrema.LowerDistance(): ", aExtrema.LowerDistance())
    if aExtrema.NbExtrema() > 0 and aExtrema.LowerDistance() < 1e-10 :  #两曲线有交点，且两曲线的最小距离为0，即有交点
        print("if is in ")
        for iPnt in range(aExtrema.NbExtrema()):
            print("for is in ")
            aPnt1 = gp_Pnt()
            aPnt2 = gp_Pnt()
            
            aExtrema.Points(iPnt + 1, aPnt1, aPnt2) #两个点的坐标
            print("aPnt1: ", aPnt1)
            if aPnt1.SquareDistance(aPnt2) < 1e-15 :#两个点是同一个点，即交点
                start_pnts.append(aPnt1.X())     
  
    anEdgeExplorer.Next() # 下一个子形状
    
print("start_pnts: ", start_pnts)

 

 

本文地址：https://blog.csdn.net/reyyy/article/details/107319187