import logging
import numpy as _np
from openpnm.io import _parse_filename
logger = logging.getLogger(__name__)
[docs]
def network_to_stl(network, filename=None, maxsize='auto',
fileformat='STL Format', logger_level=0):
r"""
Saves (transient/steady-state) data from the given objects into the
specified file.
Parameters
----------
network : Network.
The network containing the desired data.
phases : list[Phase] (place holder, default is None).
List of phases containing the desired data.
filename : str (optional).
The name of the file containing the data to export.
maxsize : a float or a string "auto" (optional).
The maximum size of the mesh elements allowed. "auto" corresponds
to an automatic determination based on pores and throats sizes. Any
float value will be used as a maximum size. Small values result in
finner meshes, but slower mesh calculations.
fileformat : str (optional).
Default is "STL Format" which corresponds to STL format. Other
formats such as Gmsh and Fluent are supported (see ngsolve.org).
logger_level : integer between 0 and 7 (optional).
Default is 0. The logger level set in netgen package.
Notes
-----
The STL Format is a Standard Triangle (or Tessellation) Language supported
by many CAD packages and used for 3D printing. Export to this format may be
slow since a 3D closed surface mesh is built.
Requires installation of "netgen".
"""
try:
import netgen.csg as csg
except ModuleNotFoundError:
raise Exception('Module "netgen" not found.')
try:
from netgen.meshing import SetMessageImportance as log
log(logger_level)
except ModuleNotFoundError:
logger.warning('Module "netgen.meshing" not found.'
+ ' The "logger_level" will be ignored.')
# Temporarily add endpoints to network so STL class works
network["throat.endpoints.head"] = network.coords[network.conns[:, 0]]
network["throat.endpoints.tail"] = network.coords[network.conns[:, 1]]
filename = network.name if filename is None else filename
path = _parse_filename(filename=filename, ext='stl')
# Path is a pathlib object, so slice it up as needed
fname_stl = path.name
# Correct connections where 'pore.diameter' = 'throat.diameter'
dt = network['throat.diameter'].copy()
dp = network['pore.diameter'][network['throat.conns']]
dt[dp[:, 0] == dt] *= 0.99
dt[dp[:, 1] == dt] *= 0.99
scale = max(network['pore.diameter'].max(), dt.max(),
network['throat.length'].max())
if maxsize == 'auto':
maxsize = min(network['pore.diameter'].min(), dt.min(),
network['throat.length'].min())
geo = csg.CSGeometry()
# Define pores
geometry = csg.Sphere(csg.Pnt(network['pore.coords'][0, 0]/scale,
network['pore.coords'][0, 1]/scale,
network['pore.coords'][0, 2]/scale),
network['pore.diameter'][0]/scale/2)
for p in range(1, network.Np):
pore = csg.Sphere(csg.Pnt(network['pore.coords'][p, 0]/scale,
network['pore.coords'][p, 1]/scale,
network['pore.coords'][p, 2]/scale),
network['pore.diameter'][p]/scale/2)
geometry += pore
# Define throats
for t in range(network.Nt):
A = network['throat.endpoints.tail'][t, :]/scale
B = network['throat.endpoints.head'][t, :]/scale
V = (B-A)/_np.linalg.norm(B-A)
plane1 = csg.Plane(csg.Pnt(A[0], A[1], A[2]),
csg.Vec(-V[0], -V[1], -V[2]))
plane2 = csg.Plane(csg.Pnt(B[0], B[1], B[2]),
csg.Vec(V[0], V[1], V[2]))
cylinder = csg.Cylinder(csg.Pnt(A[0], A[1], A[2]),
csg.Pnt(B[0], B[1], B[2]),
dt[t]/scale/2)
throat = cylinder * plane1 * plane2
geometry += throat
# Add pore and throats to geometry, build mesh, rescale, and export
geo.Add(geometry)
mesh = geo.GenerateMesh(maxh=maxsize/scale)
mesh.Scale(scale)
mesh.Export(filename=fname_stl, format=fileformat)
# Remove endpoints label from network
del network["throat.endpoints"]
