Boundary conditions of newly added csg.CSGeometry is automatically merged

import numpy as np from netgen import csg from ngsolve.comp import Mesh def cylinder(p0, p1, unit_vec, r, bc="bc"): """ a pointed cylinder (numpy interface) """ # generate CSG primitives csg_p0 = csg.Pnt(p0[0], p0[1], p0[2]) csg_p1 = csg.Pnt(p1[0], p1[1], p1[2]) csg_vec = csg.Vec(unit_vec[0], unit_vec[1], unit_vec[2]) # generate cylinder shape bot = csg.Plane(csg_p0, -csg_vec) top = csg.Plane(csg_p1, csg_vec) cy_surface = csg.Cylinder(csg_p0, csg_p1, r) # specify bc on top top.bc(bc) # geo cy = top * cy_surface * bot return cy def unit_cylinder(h=1.0, r=0.5, bc="cyl"): """ scaled unit z-axis cylinder """ p0 = [0, 0, 0] p1 = [0, 0, h] unit_vec = [0, 0, 1] return cylinder(p0, p1, unit_vec, r, bc) def electrode_cylinder(p0=[0, 0, 0], unit_vec=[1, 0, 0], shape=[0.1, 0.1], bc="e0"): """ cylinder electrode (numpy interface) shape: NDArray [radius, thickness] """ r, thick = shape # calculate the center of the other face p1 = np.asarray(p0) + thick * np.asarray(unit_vec) # generate cylinder electrode with annotation ele = cylinder(p0, p1, unit_vec, r, bc) ele.mat('agcl') return ele def cylinder_with_electrodes(): """ [test only, will be deleted] """ h = 1.0 r = 0.5 g0 = unit_cylinder(h=h, r=r) g0.mat('g0') # generate cylinder electrode ele_shape = [0.1, 0.1] # radius, thick thick = ele_shape[1] ele_pos = [30, h/2.0] # angle (degree), z # infer locations rad = ele_pos[0] * 2 * np.pi / 360.0 unit_vec = np.array([np.cos(rad), np.sin(rad), 0]) # warning: a thin contact of electrode with domain will cause # netgen failed to generate proper mesh p0 = (r - thick/2.0)*unit_vec p0[2] = ele_pos[1] # place 1st electrode ele = electrode_cylinder(p0, unit_vec, shape=ele_shape, bc="e0") # geo = g0 + ele # place 2nd electrode p0[2] += 0.25 # p0[0] += 0.01 # <-- https://github.com/NGSolve/netgen/issues/49 ele2 = electrode_cylinder(p0, unit_vec, shape=ele_shape, bc="e1") # geo = geo + ele2 ele = ele - g0 ele2 = ele2 - g0 return g0, ele, ele2 if __name__ == "__main__": g, ele, ele2 = cylinder_with_electrodes() geo = csg.CSGeometry() geo.Add(g) geo.Add(ele) geo.Add(ele2) ngmesh = geo.GenerateMesh(maxh=0.1) mesh = Mesh(ngmesh) # mesh.Curve(3) print(mesh.GetBoundaries()) print(mesh.GetMaterials())

geo.Add (cyl, bcmod=[(plane,'bc')])