example that demonstrates how to compute the minimal distance between 2 circles and 2 cubes

Author: jf---

examples/core_geometry_minimal_distance.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python
+
+##Copyright 2009-2015 Jelle Ferina (jelleferinga@gmail.com)
+##
+##This file is part of pythonOCC.
+##
+##pythonOCC is free software: you can redistribute it and/or modify
+##it under the terms of the GNU Lesser General Public License as published by
+##the Free Software Foundation, either version 3 of the License, or
+##(at your option) any later version.
+##
+##pythonOCC is distributed in the hope that it will be useful,
+##but WITHOUT ANY WARRANTY; without even the implied warranty of
+##MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+##GNU Lesser General Public License for more details.
+##
+##You should have received a copy of the GNU Lesser General Public License
+##along with pythonOCC.  If not, see <http://www.gnu.org/licenses/>.
+
+from __future__ import print_function
+
+from OCC.BRepExtrema import BRepExtrema_DistShapeShape
+from OCC.BRepPrimAPI import BRepPrimAPI_MakeBox
+from OCC.Display.SimpleGui import init_display
+from OCC.gp import gp_Pnt, gp_Ax2, gp_Circ
+
+from core_geometry_utils import make_edge, make_vertex
+
+display, start_display, add_menu, add_function_to_menu = init_display()
+
+
+def compute_minimal_distance_between_cubes():
+    """ compute the minimal distance between 2 cubes
+
+    the line between the 2 points is rendered in cyan
+
+    """
+    b1 = BRepPrimAPI_MakeBox(gp_Pnt(100, 0, 0), 10., 10., 10.).Shape()
+    b2 = BRepPrimAPI_MakeBox(gp_Pnt(45, 45, 45), 10., 10., 10.).Shape()
+    display.DisplayShape([b1, b2])
+
+    dss = BRepExtrema_DistShapeShape()
+    dss.LoadS1(b1)
+    dss.LoadS2(b2)
+    dss.Perform()
+
+    assert dss.IsDone()
+
+    edg = make_edge(dss.PointOnShape1(1), dss.PointOnShape2(1))
+    display.DisplayColoredShape([edg], color="CYAN")
+
+
+def compute_minimal_distance_between_circles():
+    """ compute the minimal distance between 2 circles
+
+    here the minimal distance overlaps the intersection of the circles
+    the points are rendered to indicate the locations
+
+    """
+    # required for precise rendering of the circles
+    display.Context.SetDeviationCoefficient(0.0001)
+    L = gp_Pnt(4, 10, 0)
+    M = gp_Pnt(10, 16, 0)
+
+    Laxis = gp_Ax2()
+    Maxis = gp_Ax2()
+    Laxis.SetLocation(L)
+    Maxis.SetLocation(M)
+
+    r1 = 12.0
+    r2 = 15.0
+    Lcircle = gp_Circ(Laxis, r1)
+    Mcircle = gp_Circ(Maxis, r2)
+
+    l_circle, m_circle = make_edge(Lcircle), make_edge(Mcircle)
+    display.DisplayShape((l_circle, m_circle))
+
+    # compute the minimal distance between 2 circles
+    # the minimal distance here matches the intersection of the circles
+    dss = BRepExtrema_DistShapeShape(l_circle, m_circle)
+
+    print("intersection parameters on l_circle:",
+          [dss.ParOnEdgeS1(i) for i in range(1, dss.NbSolution() + 1)])
+    print("intersection parameters on m_circle:",
+          [dss.ParOnEdgeS2(i) for i in range(1, dss.NbSolution() + 1)])
+
+    for i in range(1, dss.NbSolution() + 1):
+        pnt = dss.PointOnShape1(i)
+        display.DisplayShape(make_vertex(pnt))
+
+
+if __name__ == "__main__":
+    compute_minimal_distance_between_cubes()
+    compute_minimal_distance_between_circles()
+    display.FitAll()
+    start_display()