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## ##
## Copyright (c) 2003-2009 by The University of Queensland ##
## Earth Systems Science Computational Centre (ESSCC) ##
## http://www.uq.edu.au/esscc ##
## ##
## Primary Business: Brisbane, Queensland, Australia ##
## Licensed under the Open Software License version 3.0 ##
## http://www.opensource.org/licenses/osl-3.0.php ##
## ##
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# medit2TriMesh.py: converts Medit meshes to ESyS-Particle TriMesh format
#
# Author: D. Weatherley
# Organisation: Earth Systems Science Computational Centre
# The University of Queensland, Brisbane, Australia.
# Date: 18 September 2009
#import required modules:
from math import sqrt
from sys import argv
def readMeditMesh (meshfile="corner.mesh"):
infile = open(meshfile,"r")
lines = infile.readlines()
infile.close()
nodelist = []
numNodes = int(lines[4].split()[0])
for i in range(numNodes):
nodelist.append([0,0.0,0.0,0.0])
id = 0
for line in lines[5:numNodes+5]:
data = line.split()
X = float(data[0])
Y = float(data[1])
Z = float(data[2])
nodelist[id][0] = id
nodelist[id][1] = X
nodelist[id][2] = Y
nodelist[id][3] = Z
id += 1
numTriangles = int(lines[numNodes+6].split()[0])
triList = []
for i in range(numTriangles):
triList.append([0,0,0,0])
tid = 0
for line in lines[numNodes+7:numNodes+7+numTriangles]:
data = line.split()
id1 = int(data[0])-1
id2 = int(data[1])-1
id3 = int(data[2])-1
triList[tid][0] = tid
triList[tid][1] = id1
triList[tid][2] = id2
triList[tid][3] = id3
tid += 1
return (nodelist, triList)
def writeTriMesh (nodeList, triList, outfilename="trimesh.lsm"):
outstring = "Triangle\n3D-Nodes %d\n" % (len(nodeList))
for node in nodeList:
outstring += "%d %d 0 %f %f %f\n" % (node[0],node[0],node[1],node[2],node[3])
outstring += "\nTri3 %d\n" % (len(triList))
for tri in triList:
outstring += "%d 0 %d %d %d\n" % (tri[0],tri[1],tri[2],tri[3])
outfile = open(outfilename,"w")
outfile.write(outstring)
outfile.close()
return
def normalVector(p1,p2,p3):
r1 = [p2[0]-p1[0],p2[1]-p1[1],p2[2]-p1[2]]
r2 = [p3[0]-p1[0],p3[1]-p1[1],p3[2]-p1[2]]
cp = [r2[1]*r1[2] - r2[2]*r1[1], r2[2]*r1[0] - r2[0]*r1[2], r2[0]*r1[1] - r2[1]*r1[0]]
norm = sqrt(cp[0]*cp[0]+cp[1]*cp[1]+cp[2]*cp[2])
if (norm > 0.0):
nV = [cp[0]/norm,cp[1]/norm,cp[2]/norm]
else:
nV = [0,0,0]
return nV
def reorderNodes(nodeList, triList, inPoint = [0.5,0.5,1.0]):
for tid in range(len(triList)):
id1 = triList[tid][1]
id2 = triList[tid][2]
id3 = triList[tid][3]
p1 = [nodeList[id1][1], nodeList[id1][2], nodeList[id1][3]]
p2 = [nodeList[id2][1], nodeList[id2][2], nodeList[id2][3]]
p3 = [nodeList[id3][1], nodeList[id3][2], nodeList[id3][3]]
nV = normalVector(p1,p2,p3)
dp = [inPoint[0]-p1[0],inPoint[1]-p1[1],inPoint[2]-p1[2]]
dp_nV = dp[0]*nV[0] + dp[1]*nV[1] + dp[2]*nV[2]
if (dp_nV < 0):
triList[tid][1] = id3
triList[tid][3] = id1
return
def Medit2TriMesh (meshfile="corner.mesh", outfile="corner.lsm",inPoint = [0.5,0.5,1.0]):
(nodeList, triList) = readMeditMesh(meshfile=meshfile)
reorderNodes (nodeList, triList, inPoint = inPoint)
writeTriMesh (nodeList,triList,outfilename=outfile)
return
if __name__ == "__main__":
if (len(argv)>=3):
Medit2TriMesh(meshfile=argv[1],outfile=argv[2],inPoint=[0,10,0])
else:
Medit2TriMesh(meshfile="bucket.mesh",outfile="bucket.lsm",inPoint=[0,5,0])
