interpolate microstructure using Delaunay triangulation and Barycentric interpolation.

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Chen Zhang 2015-02-27 22:59:09 +00:00
parent 0a144b9fa7
commit 1742725963
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#!/usr/bin/env python
##
# This script will read in all the seeds and partition the space
# using scipy.spatial.Delaunay triangulation.
# The unknown location will be then interpolated through Barycentric
# interpolation method, which relies on the triangulation.
# A rim will be automatically added to the patch, which will help
# improve the compatibility with the spectral solver as well as
# maintain meaningful microstructure(reduce artifacts).
import sys, os
import numpy as np
import argparse
from scipy.spatial import Delaunay
scriptID = string.replace('$Id$','\n','\\n')
scriptName = os.path.splitext(scriptID.split()[1])[0]
OFFSET = 0.1 #resize the seeded volume to give space for rim/pan
PHANTOM_ID = -1 #grain ID for phantom seeds
def d_print(info, data, separator=False):
'''quickly print debug information'''
if(separator): print "*"*80
print info
print data
#prepare command line interface
parser = argparse.ArgumentParser(prog="geoFromBarycentic",
description='''Generate geom file through \
Barycentric interpolating seeds file.''',
epilog="requires numpy, scipy, and \
ezxtal(https://github.com/KedoKudo/ezxtal.git).")
parser.add_argument("seeds",
help="seeds file in DAMASK format:\
http://damask.mpie.de/Documentation/AsciiTableFormat",
default="test.seeds")
parser.add_argument("-v", "--version",
action="version",
version="%(prog)s 0.1")
parser.add_argument("-g", "--grid",
nargs=3,
help="grid size(mesh resolution, recommend using 2^x)",
default=[32,32,32],
type=int)
parser.add_argument("-s", "--size",
help="physical size of the target volume.",
nargs=3,
default=[1.0,1.0,1.0],
type=float)
parser.add_argument("-o", "--origin",
help="lower left corner of the patch.",
nargs=3,
default=[0.0,0.0,0.0],
type=float)
parser.add_argument('-m', '--homogenization',
help='homogenization index to be used',
default=1,
type=int)
parser.add_argument('-c', '--crystallite',
help='crystallite index to be used',
default=1,
type=int)
parser.add_argument('-p', '--phase',
help='phase index to be used',
default=1,
type=int)
parser.add_argument('-F', '--Favg',
help='reshape the periodicity, not useful for RIM method',
nargs=9,
default=[1.0,0.0,0.0,
0.0,1.0,0.0,
0.0,0.0,1.0],
type=float)
parser.add_argument("-G", "--geomFile",
help='the name of the output geom file',
default='seeds.geom',
type=str)
parser.add_argument("-C", "--configFile",
help='output dummy material.config file',
action='store_true',
default=False)
parser.add_argument("-d", "--debug",
help="start debugging script",
action='store_true',
default=False)
parser.add_argument("-S", "--seedsFile",
help="write out resized seeds file",
action='store_true',
default=False)
parser.add_argument("-r", '--addRim',
help="add rim and provide control of face lifting point",
action='store_true',
default=False)
args = parser.parse_args() # get all the arguments right after
#quick help to user
print "*"*80
parser.print_help()
print '''Sample usage:
./geoFromBarycentic.py 20grains.seeds -g 128 128 128 -S -r; geom_check seeds.geom; seeds_check new_seed.seeds.
'''
print "*"*80
if (args.debug):
d_print("args are:", parser.parse_args(),separator=True)
#/\/\/\/\/#
# m a i n #
#\/\/\/\/\#
print "only work for 3D case now, 2D support coming soon..."
print "reading seeds file: {}".format(args.seeds)
with open(args.seeds, 'r') as f:
rawtext = f.readlines()
n_header = int(rawtext.pop(0).split()[0])
#record all the seeds position
if (args.addRim):
grid_shift = np.array(args.size) * np.array([OFFSET,OFFSET,OFFSET*2])
s_coords = np.array([[np.array(float(item))*(1 - OFFSET*2)
for item in line.split()[:3]] + grid_shift
for line in rawtext[n_header:]])
else:
#no need for shifting with periodicity
s_coords = np.array([[np.array(float(item))
for item in line.split()[:3]]
for line in rawtext[n_header:]])
#record ID of the seeds: int/EulerAngles
if 'microstructure' in rawtext[n_header-1]:
s_id = [int(line.split()[-1]) for line in rawtext[n_header:]]
else:
print "WARNING:"
print "THIS SCRIPT DOES NOT UNDERSTAND HOW TO GROUP CRYSTALLITES."
print "ALL CRYSTAL ORIENTATIONS ARE CONSIDERED TO BE UNIQUE."
print "FOR MORE ACCURATE CONTROL OF SEEDS GROUPING, USE MICROSTRUCTURE ID."
s_id = range(len(s_coords))
#s_eulers here is just a quick book keeping
s_eulers = np.array([[float(item) for item in line.split()[3:]]
for line in rawtext[n_header:]])
if(args.debug):
print d_print("resize point cloud to make space for rim/pan:",
s_coords)
if(args.addRim):
#add binding box to create rim/pan for the volume where the ID of the seeds is
#unknown
print "Shrining the seeds to {}x in each direction".format(1 - OFFSET*2)
x,y,z = args.size[0],args.size[1],args.size[2]
print "Use circumscribed sphere to place phantom seeds."
r = np.sqrt(x**2+y**2+z**2)/2.0
BINDBOX = [[0,0,0],[x,0,0],[0,y,0],[x,y,0],
[0,0,z],[x,0,z],[0,y,z],[x,y,z],
[x/2.0+r,y/2, z/2], [x/2.0-r, y/2, z/2],
[x/2, y/2.0+r, z/2], [x/2, y/2.0-r, z/2],
[x/2, y/2, z/2.0-r]] #8 corners + 5 face centers (no top)
print "Adding phantom seeds for RIM generation:"
for point in BINDBOX:
print point
s_coords = np.vstack([s_coords,point])
s_id.append(PHANTOM_ID)
else:
#The idea here is that we read in each seed point, than duplicate in 3D (make a few copies),
#move on to the next seed point, repeat the same procedure. As for the ID list, we can just use the
#same one. The trick here is use the floor division to find the correct id since we pretty much duplicate
#the same point several times.
Favg = np.array(args.Favg).reshape((3,3))
x,y,z = args.size[0],args.size[1],args.size[2]
tmp = []
for seed in s_coords:
tmp += [np.dot(Favg, np.array(seed) + np.array([dx,dy,dz]))
for dz in [-z, 0, z]
for dy in [-y, 0, y]
for dx in [-x, 0, x]]
s_coords = tmp
for item in tmp:
print item
if (args.seedsFile):
with open("new_seed.seeds", "w") as f:
outstr = "4\theader\n"
outstr += "grid\ta {}\tb {}\tc {}\n".format(args.grid[0],
args.grid[1],
args.grid[2])
outstr += "microstructures {}\n".format(len(set(s_id)))
outstr += "randomSeed 0\n"
outstr += "x\ty\tz\tmicrostructure"
if (args.addRim):
for i in range(len(s_id)):
outstr += "{}\t{}\t{}\t{}\n".format(s_coords[i][0],
s_coords[i][1],
s_coords[i][2],
s_id[i])
else:
for i in range(len(s_coords)):
outstr += "{}\t{}\t{}\t{}\n".format(s_coords[i][0],
s_coords[i][1],
s_coords[i][2],
s_id[i//3**3])
f.write(outstr)
#triangulate space with given point-clouds
tri = Delaunay(s_coords)
if(args.debug):
d_print("simplices:", tri.simplices, separator=True)
d_print("vertices:", s_coords[tri.simplices])
#populate grid points (only 3D for now)
mesh_pts = [[(i+0.5)*args.size[0]/args.grid[0],
(j+0.5)*args.size[1]/args.grid[1],
(k+0.5)*args.size[2]/args.grid[2]]
for k in range(args.grid[2])
for j in range(args.grid[1])
for i in range(args.grid[0])]
mesh_ids = [PHANTOM_ID*2]*len(mesh_pts) #initialize grid
#search ID for each grid point
s_id = np.array(s_id) #allow multi-indexing
mesh_idx = tri.find_simplex(mesh_pts)
for i, pt in enumerate(mesh_pts):
if mesh_idx[i] < 0:
continue #didn't find any envelop tetrahedron --> something wrong!
#calculate Barycentric coordinates
bary_c = tri.transform[mesh_idx[i],:3,:3].dot(pt-tri.transform[mesh_idx[i],3,:])
bary_c = np.append(bary_c, 1 - bary_c.sum())
if (args.addRim):
tmp_ids = s_id[tri.simplices[mesh_idx[i]]] #rim method
else:
tmp_ids = np.array(s_id[tri.simplices[mesh_idx[i]]//(3**3)]) #kill periodicity through floor division
#print tmp_ids
#print tri.simplices[mesh_idx[i]]//(3**3)
max_weight = -1960
for this_id in tmp_ids:
msk = [item==this_id for item in tmp_ids] #find vertex with the same id
tmp_weight = sum([bary_c[j] for j in range(len(bary_c)) if msk[j]])
if tmp_weight > max_weight:
max_weight = tmp_weight
mesh_ids[i] = this_id
if (args.debug):
d_print("bary_c:",bary_c,separator=True)
d_print("vertex ID:", tmp_ids)
d_print("final ID:", mesh_ids[i])
mesh_ids = np.reshape(mesh_ids, (-1, args.grid[0]))
#write to file
with open(args.geomFile, "w") as f:
outstr = "5\theader\n"
outstr += "grid\ta {}\tb {}\tc {}\n".format(args.grid[0],
args.grid[1],
args.grid[2])
outstr += "size\tx {}\ty {}\tz {}\n".format(args.size[0],
args.size[1],
args.size[2])
outstr += "origin\tx {}\ty {}\tz {}\n".format(args.origin[0],
args.origin[1],
args.origin[2])
outstr += "homogenization\t{}\nmicrostructure\t{}\n".format(args.homogenization,
len(set(s_id)))
for row in mesh_ids:
row = [str(item) for item in list(row)]
outstr += "\t".join(row) + "\n"
f.write(outstr)