def loadMsh(filename, crs, outputdir):
progress = QtWidgets.QProgressDialog("Converting GMSH mesh...", "Abort", 0,
100)
progress.setMinimumDuration(1000)
progress.setWindowModality(Qt.WindowModal)
QDir().mkpath(outputdir)
fin = open(filename, "r")
l = fin.readline()
useFormat3 = False
vertices = {}
physicalNames = {}
entityPhysical = {}
physicalWriter = {}
entityWriter = {}
def abort():
for writer in physicalWriter.values():
QgsVectorFileWriter.deleteShapeFile(writer.path + ".shp")
QFile.remove(writer.path + ".cpg")
while l != "":
w = l.split()
if w[0] == "$MeshFormat":
l = fin.readline().split()
if int(float(l[0])) == 3:
useFormat3 = True
elif int(float(l[0])) == 2:
useFormat3 = False
else:
raise ValueError("cannot read mesh format " + l[0])
l = fin.readline()
elif w[0] == "$PhysicalNames":
n = int(fin.readline())
for i in range(n):
dim, tag, name = fin.readline().split()
physicalNames[(int(dim), int(tag))] = name[1:-1]
fin.readline()
elif w[0] == "$Entities" and useFormat3:
ns = list(int(fin.readline()) for i in range(4))
for dim in range(4):
for i in range(ns[dim]):
l = fin.readline().split()
j, nbnd = int(l[0]), int(l[1])
nphys = int(l[2 + nbnd])
entityPhysical[(dim,
j)] = int(l[2 + nbnd +
nphys]) if nphys > 0 else None
elif w[0] == "$Nodes":
n = int(fin.readline())
for i in range(n):
if i % 1000 == 0:
QtWidgets.QApplication.processEvents()
progress.setValue((7 * i) / n)
if progress.wasCanceled():
abort()
return
if useFormat3:
j, x, y, z = fin.readline().split()[:4]
else:
(j, x, y, z) = fin.readline().split()
vertices[int(j)] = [float(x), float(y), float(z), int(j)]
elif w[0] == "$Elements":
n = int(fin.readline())
for i in range(n):
if i % 100 == 0:
QtWidgets.QApplication.processEvents()
if progress.wasCanceled():
abort()
return
if i % 1000 == 0:
progress.setValue(7 + (93 * i) / n)
l = fin.readline().split()
if useFormat3:
j, t, e, nf = int(l[0]), int(l[1]), int(l[2]), int(l[3])
nv = gmshType.Type[t].numVertices
evertices = [vertices[int(i)] for i in l[4:4 + nv]]
partition = [
int(i) for i in l[5 + nv:5 + nv + int(l[4 + nv])]
] if nf > nv else []
else:
j, t, nf, p, e = int(l[0]), int(l[1]), int(l[2]), int(
l[3]), int(l[4])
evertices = [vertices[int(i)] for i in l[3 + nf:]]
partition = [int(i)
for i in l[6:6 +
int(l[5])]] if nf > 2 else []
edim = gmshType.Type[t].baseType.dimension
writer = entityWriter.get((edim, e), None)
if writer is None:
if useFormat3:
if (edim, e) in entityPhysical:
p = entityPhysical[(edim, e)]
else:
p = 0
writer = physicalWriter.get((edim, p), None)
if writer is None:
fields = QgsFields()
ltype = [
QgsWkbTypes.Point, QgsWkbTypes.LineString,
QgsWkbTypes.Polygon
][edim]
name = physicalNames.get((edim, p), None)
if name is None:
name = ["points", "lines", "elements"
][edim] + ("_" + str(p) if p >= 0 else "")
physicalNames[(edim, p)] = name
path = os.path.join(outputdir, name)
writer = QgsVectorFileWriter(
path,
"system",
fields,
ltype,
crs,
driverName="ESRI Shapefile")
writer.path = path
physicalWriter[(edim, p)] = writer
entityWriter[(edim, e)] = writer
points = list([QgsPointXY(v[0], v[1]) for v in evertices])
if edim == 0:
geom = QgsGeometry.fromPointXY(points[0])
elif edim == 1:
geom = QgsGeometry.fromPolylineXY(points)
elif edim == 2:
v = evertices[0]
points.append(QgsPointXY(v[0], v[1]))
geom = QgsGeometry.fromPolygonXY([points])
feature = QgsFeature()
feature.setGeometry(geom)
writer.addFeature(feature)
l = fin.readline()
group = QgsProject.instance().layerTreeRoot().addGroup("mesh")
paths = []
for writer in physicalWriter.values():
paths.append(writer.path + ".shp")
del writer
QThread.sleep(1)
progress.setValue(100)
for path in paths:
l = QgsVectorLayer(path, QFileInfo(path).baseName(), "ogr")
QgsProject.instance().addMapLayer(l, False)
group.addLayer(l)
