動作環境
GeForce GTX 1070 (8GB)
ASRock Z170M Pro4S [Intel Z170chipset]
Ubuntu 16.04 LTS desktop amd64
TensorFlow v1.2.1
cuDNN v5.1 for Linux
CUDA v8.0
Python 3.5.2
IPython 6.0.0 -- An enhanced Interactive Python.
gcc (Ubuntu 5.4.0-6ubuntu1~16.04.4) 5.4.0 20160609
GNU bash, version 4.3.48(1)-release (x86_64-pc-linux-gnu)
scipy v0.19.1
geopandas v0.3.0
MATLAB R2017b (Home Edition)
背景
MATLAB > freeBoundary()を試してみた > tetmeshを処理してみた > 疑問点
MATLABにはfreeBoundary()というAPIがある。Numpyのビルトインにはない。
freeBoundaryの処理は以下なのだろう。
MATLAB > freeBoundary() > 四面体結合物への適用 > 隠面以外の三角形の情報を取得する
処理概要
- 四面体結合体から三角形のインデックス組合せを取得する
- 隠面を除く
テストデータ
MATLAB > 四面体メッシュプロット > tetramesh() | view(30,30) | サブセット表示 tetramesh(tet(2:3,:),X)
v0.1 > ２つの四面体
code
Matplotlibで動作確認しているが、Numpy環境でも動くだろう。
freeBoundary_171112.ipynb
import numpy as np
'''
v0.1 Nov. 12, 2017
- Test_get_shown_triangles()
- is_same_list()
- add get_shown_triangles()
- add get_triangle_sets()
- add find_hidden_triangleIndex()
'''
# on Python 3.5.2
# coding rule:PEP8
def find_hidden_triangleIndex(tris):
overlap = []
for lidx in range(len(tris) - 1):
for ridx in range(len(tris)):
if lidx == ridx:
continue
wrk = []
for elem in tris[lidx]:
if elem in tris[ridx]:
wrk += [elem]
if (len(wrk) == 3):
overlap += [wrk]
return overlap
def get_triangle_sets(tris):
idx1 = [0, 1, 2]
idx2 = [0, 1, 3]
idx3 = [0, 2, 3]
idx4 = [1, 2, 3]
wrk = []
for lidx in range(len(tris)):
wrk += [tris[lidx][idx1]]
wrk += [tris[lidx][idx2]]
wrk += [tris[lidx][idx3]]
wrk += [tris[lidx][idx4]]
return wrk
def is_same_list(lhs, rhs):
cnt = 0
for lelem in lhs:
if lelem in rhs:
cnt += 1
return (cnt == 3)
def get_shown_triangles(trihdns, triall):
wrk = []
for atri in triall:
ishidden = False
for ahidden in trihdns:
if is_same_list(ahidden, atri):
ishidden = True
if not ishidden:
wrk += [atri]
return wrk
def Test_get_shown_triangles():
tri1 = [1092, 856, 1094, 1095] # index of triangles for tetrahedra
tri2 = [1092, 1095, 896, 856] # index of triangles for tetrahedra
tris = [np.array(tri1), np.array(tri2)]
trihdn = find_hidden_triangleIndex(tris)
print('hidden:', trihdn)
triall = get_triangle_sets(tris)
#
trishown = get_shown_triangles(trihdn, triall)
print('---except for hidden---')
for elem in trishown:
print(elem)
if __name__ == '__main__':
Test_get_shown_triangles()
run
hidden: [[1092, 856, 1095]]
---except for hidden---
[1092 856 1094]
[1092 1094 1095]
[ 856 1094 1095]
[1092 1095 896]
[1092 896 856]
[1095 896 856]
2つの四面体でのテストはできた。
v0.2 > 3つの四面体
データ
MATLABコード。
以下のインデックスで３つの四面体結合になっていた。
>> load tetmesh
>> tetramesh(tet(106:108,:),X)
>> view(60,0)
>> tet(106:108,:)
ans =
1098 1175 1170 1204
1098 1170 1175 1172
1098 1170 1203 1204
code
freeBoundary_171112.ipynb
import numpy as np
'''
v0.2 Nov. 12, 2017 test with 3 tetrahedra
- add Test_get_shown_triangles_3tetrahedra()
v0.1 Nov. 12, 2017
- Test_get_shown_triangles()
- is_same_list()
- add get_shown_triangles()
- add get_triangle_sets()
- add find_hidden_triangleIndex()
'''
# on Python 3.5.2
# coding rule:PEP8
def find_hidden_triangleIndex(tris):
overlap = []
for lidx in range(len(tris) - 1):
for ridx in range(len(tris)):
if lidx == ridx:
continue
wrk = []
for elem in tris[lidx]:
if elem in tris[ridx]:
wrk += [elem]
if (len(wrk) == 3):
overlap += [wrk]
return overlap
def get_triangle_sets(tris):
idx1 = [0, 1, 2]
idx2 = [0, 1, 3]
idx3 = [0, 2, 3]
idx4 = [1, 2, 3]
wrk = []
for lidx in range(len(tris)):
wrk += [tris[lidx][idx1]]
wrk += [tris[lidx][idx2]]
wrk += [tris[lidx][idx3]]
wrk += [tris[lidx][idx4]]
return wrk
def is_same_list(lhs, rhs):
cnt = 0
for lelem in lhs:
if lelem in rhs:
cnt += 1
return (cnt == 3)
def get_shown_triangles(trihdns, triall):
wrk = []
for atri in triall:
ishidden = False
for ahidden in trihdns:
if is_same_list(ahidden, atri):
ishidden = True
if not ishidden:
wrk += [atri]
return wrk
def Test_get_shown_triangles():
tri1 = [1092, 856, 1094, 1095] # index of triangles for tetrahedra
tri2 = [1092, 1095, 896, 856] # index of triangles for tetrahedra
tris = [np.array(tri1), np.array(tri2)]
trihdn = find_hidden_triangleIndex(tris)
print('hidden:', trihdn)
triall = get_triangle_sets(tris)
#
trishown = get_shown_triangles(trihdn, triall)
print('---except for hidden---')
for elem in trishown:
print(elem)
def Test_get_shown_triangles_3tetrahedra():
tri1 = [1098, 1175, 1170, 1204] # index of triangles for tetrahedra
tri2 = [1098, 1170, 1175, 1172] # index of triangles for tetrahedra
tri3 = [1098, 1170, 1203, 1204] # index of triangles for tetrahedra
tris = [np.array(tri1), np.array(tri2), np.array(tri3)]
trihdn = find_hidden_triangleIndex(tris)
print('hidden:', trihdn)
triall = get_triangle_sets(tris)
#
trishown = get_shown_triangles(trihdn, triall)
print('---except for hidden---')
for elem in trishown:
print(elem)
if __name__ == '__main__':
# Test_get_shown_triangles()
Test_get_shown_triangles_3tetrahedra()
run
hidden: [[1098, 1175, 1170], [1098, 1170, 1204], [1098, 1170, 1175]]
---except for hidden---
[1098 1175 1204]
[1175 1170 1204]
[1098 1170 1172]
[1098 1175 1172]
[1170 1175 1172]
[1098 1170 1203]
[1098 1203 1204]
[1170 1203 1204]
4 x 3 - 4 = 8
期待通りになっている。