# -*- coding: utf-8 -*-
"""
$Id$
Copyright 2008-2010 Lode Leroy
Copyright 2010 Lars Kruse <devel@sumpfralle.de>
This file is part of PyCAM.
PyCAM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
PyCAM 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with PyCAM. If not, see <http://www.gnu.org/licenses/>.
"""
from pycam.Geometry.PointUtils import *
from pycam.Geometry.Triangle import Triangle
from pycam.Geometry.PointKdtree import PointKdtree
from pycam.Geometry.utils import epsilon
from pycam.Geometry.Model import Model
import pycam.Utils.log
import pycam.Utils
from struct import unpack
import StringIO
import re
log = pycam.Utils.log.get_logger()
vertices = 0
edges = 0
kdtree = None
lastUniqueVertex = (None,None,None)
def UniqueVertex(x, y, z):
global vertices,lastUniqueVertex
if kdtree:
p = kdtree.Point(x, y, z)
if p == lastUniqueVertex:
vertices += 1
return p
else:
vertices += 1
return (x, y, z)
def ImportModel(filename, use_kdtree=True, callback=None, **kwargs):
global vertices, edges, kdtree
vertices = 0
edges = 0
kdtree = None
normal_conflict_warning_seen = False
if hasattr(filename, "read"):
# make sure that the input stream can seek and has ".len"
f = StringIO.StringIO(filename.read())
# useful for later error messages
filename = "input stream"
else:
try:
url_file = pycam.Utils.URIHandler(filename).open()
# urllib.urlopen objects do not support "seek" - so we need to read
# the whole file at once. This is ugly - anyone with a better idea?
f = StringIO.StringIO(url_file.read())
# TODO: the above ".read" may be incomplete - this is ugly
# see http://patrakov.blogspot.com/2011/03/case-of-non-raised-exception.html
# and http://stackoverflow.com/questions/1824069/urllib2-not-retrieving-entire-http-response
url_file.close()
except IOError, err_msg:
log.error("STLImporter: Failed to read file (%s): %s" \
% (filename, err_msg))
return None
# Read the first two lines of (potentially non-binary) input - they should
# contain "solid" and "facet".
header_lines = []
while len(header_lines) < 2:
line = f.readline(200)
if len(line) == 0:
# empty line (not even a line-feed) -> EOF
log.error("STLImporter: No valid lines found in '%s'" % filename)
return None
# ignore comment lines
# note: partial comments (starting within a line) are not handled
if not line.startswith(";"):
header_lines.append(line)
header = "".join(header_lines)
# read byte 80 to 83 - they contain the "numfacets" value in binary format
f.seek(80)
numfacets = unpack("<I", f.read(4))[0]
binary = False
log.debug("STL import info: %s / %s / %s / %s" % \
(f.len, numfacets, header.find("solid"), header.find("facet")))
if f.len == (84 + 50*numfacets):
binary = True
elif header.find("solid") >= 0 and header.find("facet") >= 0:
binary = False
f.seek(0)
else:
log.error("STLImporter: STL binary/ascii detection failed")
return None
if use_kdtree:
kdtree = PointKdtree([], 3, 1, epsilon)
model = Model(use_kdtree)
t = None
p1 = None
p2 = None
p3 = None
if binary:
for i in range(1, numfacets + 1):
if callback and callback():
log.warn("STLImporter: load model operation cancelled")
return None
a1 = unpack("<f", f.read(4))[0]
a2 = unpack("<f", f.read(4))[0]
a3 = unpack("<f", f.read(4))[0]
n = (float(a1), float(a2), float(a3), 'v')
v11 = unpack("<f", f.read(4))[0]
v12 = unpack("<f", f.read(4))[0]
v13 = unpack("<f", f.read(4))[0]
p1 = UniqueVertex(float(v11), float(v12), float(v13))
v21 = unpack("<f", f.read(4))[0]
v22 = unpack("<f", f.read(4))[0]
v23 = unpack("<f", f.read(4))[0]
p2 = UniqueVertex(float(v21), float(v22), float(v23))
v31 = unpack("<f", f.read(4))[0]
v32 = unpack("<f", f.read(4))[0]
v33 = unpack("<f", f.read(4))[0]
p3 = UniqueVertex(float(v31), float(v32), float(v33))
# not used
attribs = unpack("<H", f.read(2))
dotcross = pdot(n, pcross(psub(p2, p1), psub(p3, p1)))
if a1 == a2 == a3 == 0:
dotcross = pcross(psub(p2, p1), psub(p3,p1))[2]
n = None
if dotcross > 0:
# Triangle expects the vertices in clockwise order
t = Triangle(p1, p3, p2)
elif dotcross < 0:
if not normal_conflict_warning_seen:
log.warn(("Inconsistent normal/vertices found in facet " + \
"definition %d of '%s'. Please validate the " + \
"STL file!") % (i, filename))
normal_conflict_warning_seen = True
t = Triangle(p1, p2, p3)
else:
# the three points are in a line - or two points are identical
# usually this is caused by points, that are too close together
# check the tolerance value in pycam/Geometry/PointKdtree.py
log.warn("Skipping invalid triangle: %s / %s / %s " \
% (p1, p2, p3) + "(maybe the resolution of the model " \
+ "is too high?)")
continue
if n:
t.normal = n
model.append(t)
else:
solid = re.compile(r"\s*solid\s+(\w+)\s+.*")
endsolid = re.compile(r"\s*endsolid\s*")
facet = re.compile(r"\s*facet\s*")
normal = re.compile(r"\s*facet\s+normal" \
+ r"\s+(?P<x>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)" \
+ r"\s+(?P<y>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)" \
+ r"\s+(?P<z>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)\s+")
endfacet = re.compile(r"\s*endfacet\s+")
loop = re.compile(r"\s*outer\s+loop\s+")
endloop = re.compile(r"\s*endloop\s+")
vertex = re.compile(r"\s*vertex" \
+ r"\s+(?P<x>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)" \
+ r"\s+(?P<y>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)" \
+ r"\s+(?P<z>[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?)\s+")
current_line = 0
for line in f:
if callback and callback():
log.warn("STLImporter: load model operation cancelled")
return None
current_line += 1
m = solid.match(line)
if m:
model.name = m.group(1)
continue
m = facet.match(line)
if m:
m = normal.match(line)
if m:
n = (float(m.group('x')), float(m.group('y')), float(m.group('z')), 'v')
else:
n = None
continue
m = loop.match(line)
if m:
continue
m = vertex.match(line)
if m:
p = UniqueVertex(float(m.group('x')), float(m.group('y')),
float(m.group('z')))
if p1 is None:
p1 = p
elif p2 is None:
p2 = p
elif p3 is None:
p3 = p
else:
log.error("STLImporter: more then 3 points in facet " \
+ "(line %d)" % current_line)
continue
m = endloop.match(line)
if m:
continue
m = endfacet.match(line)
if m:
if p1 is None or p2 is None or p3 is None:
log.warn(("Invalid facet definition in line " \
+ "%d of '%s'. Please validate the STL file!") \
% (current_line, filename))
n, p1, p2, p3 = None, None, None, None
continue
if not n:
n = pnormalized(pcross(psub(p2, p1), psub(p3, p1)))
# validate the normal
# The three vertices of a triangle in an STL file are supposed
# to be in counter-clockwise order. This should match the
# direction of the normal.
if n is None:
# invalid triangle (zero-length vector)
dotcross = 0
else:
# make sure the points are in ClockWise order
dotcross = pdot(n, pcross(psub(p2,p1), psub(p3, p1)))
if dotcross > 0:
# Triangle expects the vertices in clockwise order
t = Triangle(p1, p3, p2, n)
elif dotcross < 0:
if not normal_conflict_warning_seen:
log.warn(("Inconsistent normal/vertices found in " + \
"line %d of '%s'. Please validate the STL " + \
"file!") % (current_line, filename))
normal_conflict_warning_seen = True
t = Triangle(p1, p2, p3, n)
else:
# The three points are in a line - or two points are
# identical. Usually this is caused by points, that are too
# close together. Check the tolerance value in
# pycam/Geometry/PointKdtree.py.
log.warn("Skipping invalid triangle: %s / %s / %s " \
% (p1, p2, p3) + "(maybe the resolution of the " \
+ "model is too high?)")
n, p1, p2, p3 = (None, None, None, None)
continue
n, p1, p2, p3 = (None, None, None, None)
model.append(t)
continue
m = endsolid.match(line)
if m:
continue
log.info("Imported STL model: %d vertices, %d edges, %d triangles" \
% (vertices, edges, len(model.triangles())))
vertices = 0
edges = 0
kdtree = None
if not model:
# no valid items added to the model
return None
else:
return model