faceFromPoints.py

#!/usr/bin/env python

from OCC.Utils.Construct import make_closed_polygon, make_n_sided, make_vertex, make_face, make_wire

from OCC.gp import *
from OCC.BRepBuilderAPI import *

from OCC.Utils.Topology import WireExplorer, Topo
from OCC.BRepAdaptor import *
from OCC.BRep import *
from OCC.ShapeAnalysis import *
from OCC.GeomLProp import *

import types, sys, time, random

from OCC.Display.SimpleGui import init_display
from OCC.Utils.DataExchange.IGES import IGESImporter
from OCC.BRepFill import *
from OCC.GeomPlate import *

display, start_display, add_menu, add_function_to_menu = init_display()

def build_plate(polygon, points):
        '''
        build a surface from a constraining polygon(s) and point(s)
        @param polygon:  list of polygons ( TopoDS_Shape)
        @param points:    list of points ( gp_Pnt )
        '''
        # plate surface
        bpSrf = GeomPlate_BuildPlateSurface(3,15,2)

        # add curve constraints
        for poly in polygon:
                for edg in WireExplorer(poly).ordered_edges():
                        c = BRepAdaptor_HCurve()
                        c.ChangeCurve().Initialize(edg)
                        constraint = BRepFill_CurveConstraint(c.GetHandle(), 0)
                        bpSrf.Add(constraint.GetHandle())

        # add point constraint
        for pt in points:
                bpSrf.Add(GeomPlate_PointConstraint(pt, 0).GetHandle())
                bpSrf.Perform()

        maxSeg, maxDeg, critOrder = 9,8,0
        tol  = 1e-4
        dmax = max([tol,10*bpSrf.G0Error()])

        srf = bpSrf.Surface()
        plate = GeomPlate_MakeApprox(srf, tol, maxSeg, maxDeg, dmax, critOrder)

        print type(plate.Surface())
        uMin, uMax, vMin, vMax = srf.GetObject().Bounds()

        return make_face(plate.Surface(), uMin, uMax, vMin, vMax)

def geom_plate():
        # random number of random points in xy-plane at height z
        height = 0.5
        pmax = 50
        p = 0
        ub = 1.0
        pnts = []
        while p < pmax:
                pnts.append(gp_Pnt(random.uniform(0.0,ub), random.uniform(0.0,ub), height))
                p += 1

        poly = make_closed_polygon(pnts[0:-1])
        edges = [i for i in Topo(poly).edges()]
        face = make_n_sided(edges, [pnts[-1]])

        plate = build_plate([poly], [pnts[-1]])

        #display.DisplayShape(plate)
        display.DisplayShape(edges)
        display.DisplayShape(make_vertex(pnts[-1]))
        display.DisplayShape(face, update=True)

if __name__ == "__main__":
        geom_plate()
        start_display()