mirror of
https://github.com/NGSolve/netgen.git
synced 2024-12-25 21:40:33 +05:00
74 lines
2.5 KiB
Python
74 lines
2.5 KiB
Python
from netgen.meshing import *
|
|
|
|
def ReadGmsh (filename):
|
|
f = open(filename, 'r')
|
|
|
|
mesh = Mesh(dim=3)
|
|
|
|
pointmap = { }
|
|
facedescriptormap = { }
|
|
|
|
|
|
while True:
|
|
line = f.readline()
|
|
if line == "": break
|
|
|
|
if line.split()[0]=="$Nodes":
|
|
num = int(f.readline().split()[0])
|
|
print ("reading",num,"nodes")
|
|
for i in range(num):
|
|
line = f.readline()
|
|
nodenum,x,y,z = line.split()[0:4]
|
|
pnum = mesh.Add (MeshPoint(Pnt(float(x),float(y),float(z))))
|
|
pointmap[int(nodenum)] = pnum
|
|
|
|
if line.split()[0]=="$Elements":
|
|
num = int(f.readline().split()[0])
|
|
print ("reading",num,"elements")
|
|
|
|
for i in range(num):
|
|
line = f.readline().split()
|
|
elmnum = int(line[0])
|
|
elmtype = int(line[1])
|
|
numtags = int(line[2])
|
|
tag1 = int(line[3])
|
|
|
|
if elmtype == 2: # 3-node trig
|
|
num_nodes = 3
|
|
elif elmtype == 3: # 4-node quad
|
|
num_nodes = 4
|
|
elif elmtype == 4: # 4-node tet
|
|
num_nodes = 4
|
|
else:
|
|
print ("element type", elmtype, "not implemented")
|
|
|
|
nodenums = line[3+numtags:3+numtags+num_nodes]
|
|
nodenums2 = [ pointmap[int(nn)] for nn in nodenums ]
|
|
|
|
|
|
if elmtype in [2,3]: # 2d elements
|
|
|
|
# generate facedescriptor for boundary conditon number,
|
|
# first tag is used as bc-number
|
|
# element index maps into facedescriptor array
|
|
if tag1 in facedescriptormap.keys():
|
|
fdindex = facedescriptormap[tag1]
|
|
else:
|
|
fd = FaceDescriptor(bc=tag1)
|
|
fdindex = mesh.Add(fd)
|
|
facedescriptormap[tag1] = fdindex
|
|
|
|
mesh.Add (Element2D(fdindex, nodenums2))
|
|
|
|
if elmtype == 4: # 4-node tet
|
|
nodenums2 = [ pointmap[int(nn)] for nn in nodenums ]
|
|
mesh.Add (Element3D(tag1, [nodenums2[0],nodenums2[1],nodenums2[3],nodenums2[2]]))
|
|
print (nodenums2)
|
|
# print (mesh)
|
|
# print (pointmap)
|
|
|
|
return mesh
|
|
|
|
# ReadGMSH ("test.gmsh")
|
|
|