https://www.freecadweb.org/?lang=ja
　　https://ja.osdn.net/projects/sfnet_free-cad/releases/

FreeCAD を利用して「立方体」を作成し，50x40x30 の大きさに伸縮して iges として保存
　　
　　50x40x30.html
　　50x40x30.iges.txt
　　50x40x30.iges.html
                                                                        S0000001
,,31HOpen CASCADE IGES processor 6.8,13HFilename.iges,                  G0000001
16HOpen CASCADE 6.8,31HOpen CASCADE IGES processor 6.8,32,308,15,308,15,G0000002
,1.,2,2HMM,1,0.01,15H20171221.135557,1E-007,50.,,,11,0,                 G0000003
15H20171221.135557,;                                                    G0000004
     402       1       0       0       0       0       0       000000000D0000001
     402       0       0       1       1                               0D0000002
     144       2       0       0       0       0       0       000020000D0000003
     144       0       0       1       0                               0D0000004
     108       3       0       0       0       0       0       000010000D0000005
     108       0       0       2       0                               0D0000006
     142       5       0       0       0       0       0       000010500D0000007
     142       0       0       1       0                               0D0000008
     102       6       0       0       0       0       0       000010000D0000009
     102       0       0       1       0                               0D0000010
     110       7       0       0       0       0       0       000010000D0000011
     110       0       0       1       0                               0D0000012
     110       8       0       0       0       0       0       000010000D0000013
     110       0       0       1       0                               0D0000014
     110       9       0       0       0       0       0       000010000D0000015
     110       0       0       1       0                               0D0000016
     110      10       0       0       0       0       0       000010000D0000017
     110       0       0       1       0                               0D0000018
     144      11       0       0       0       0       0       000020000D0000019
     144       0       0       1       0                               0D0000020
     108      12       0       0       0       0       0       000010000D0000021
     108       0       0       1       0                               0D0000022
     142      13       0       0       0       0       0       000010500D0000023
     142       0       0       1       0                               0D0000024
     102      14       0       0       0       0       0       000010000D0000025
     102       0       0       1       0                               0D0000026
     110      15       0       0       0       0       0       000010000D0000027
     110       0       0       1       0                               0D0000028
     110      16       0       0       0       0       0       000010000D0000029
     110       0       0       1       0                               0D0000030
     110      17       0       0       0       0       0       000010000D0000031
     110       0       0       1       0                               0D0000032
     110      18       0       0       0       0       0       000010000D0000033
     110       0       0       1       0                               0D0000034
     144      19       0       0       0       0       0       000020000D0000035
     144       0       0       1       0                               0D0000036
     108      20       0       0       0       0       0       000010000D0000037
     108       0       0       2       0                               0D0000038
     142      22       0       0       0       0       0       000010500D0000039
     142       0       0       1       0                               0D0000040
     102      23       0       0       0       0       0       000010000D0000041
     102       0       0       1       0                               0D0000042
     110      24       0       0       0       0       0       000010000D0000043
     110       0       0       1       0                               0D0000044
     110      25       0       0       0       0       0       000010000D0000045
     110       0       0       1       0                               0D0000046
     110      26       0       0       0       0       0       000010000D0000047
     110       0       0       1       0                               0D0000048
     110      27       0       0       0       0       0       000010000D0000049
     110       0       0       1       0                               0D0000050
     144      28       0       0       0       0       0       000020000D0000051
     144       0       0       1       0                               0D0000052
     108      29       0       0       0       0       0       000010000D0000053
     108       0       0       1       0                               0D0000054
     142      30       0       0       0       0       0       000010500D0000055
     142       0       0       1       0                               0D0000056
     102      31       0       0       0       0       0       000010000D0000057
     102       0       0       1       0                               0D0000058
     110      32       0       0       0       0       0       000010000D0000059
     110       0       0       1       0                               0D0000060
     110      33       0       0       0       0       0       000010000D0000061
     110       0       0       1       0                               0D0000062
     110      34       0       0       0       0       0       000010000D0000063
     110       0       0       1       0                               0D0000064
     110      35       0       0       0       0       0       000010000D0000065
     110       0       0       1       0                               0D0000066
     144      36       0       0       0       0       0       000020000D0000067
     144       0       0       1       0                               0D0000068
     108      37       0       0       0       0       0       000010000D0000069
     108       0       0       2       0                               0D0000070
     142      39       0       0       0       0       0       000010500D0000071
     142       0       0       1       0                               0D0000072
     102      40       0       0       0       0       0       000010000D0000073
     102       0       0       1       0                               0D0000074
     110      41       0       0       0       0       0       000010000D0000075
     110       0       0       1       0                               0D0000076
     110      42       0       0       0       0       0       000010000D0000077
     110       0       0       1       0                               0D0000078
     110      43       0       0       0       0       0       000010000D0000079
     110       0       0       1       0                               0D0000080
     110      44       0       0       0       0       0       000010000D0000081
     110       0       0       1       0                               0D0000082
     144      45       0       0       0       0       0       000020000D0000083
     144       0       0       1       0                               0D0000084
     108      46       0       0       0       0       0       000010000D0000085
     108       0       0       1       0                               0D0000086
     142      47       0       0       0       0       0       000010500D0000087
     142       0       0       1       0                               0D0000088
     102      48       0       0       0       0       0       000010000D0000089
     102       0       0       1       0                               0D0000090
     110      49       0       0       0       0       0       000010000D0000091
     110       0       0       1       0                               0D0000092
     110      50       0       0       0       0       0       000010000D0000093
     110       0       0       1       0                               0D0000094
     110      51       0       0       0       0       0       000010000D0000095
     110       0       0       1       0                               0D0000096
     110      52       0       0       0       0       0       000010000D0000097
     110       0       0       1       0                               0D0000098
,6,3,19,35,51,67,83;                                          0000001P0000001
144,5,1,0,7;                                                     0000003P0000002
108,1.,0.E+000,0.E+000,0.E+000,0,0.E+000,0.E+000,0.E+000,        0000005P0000003
0.E+000;                                                         0000005P0000004
142,0,5,0,9,2;                                                   0000007P0000005
102,4,11,13,15,17;                                               0000009P0000006
110,0.E+000,0.E+000,30.,0.E+000,0.E+000,0.E+000;                 0000011P0000007
110,0.E+000,0.E+000,0.E+000,0.E+000,40.,0.E+000;                 0000013P0000008
110,0.E+000,40.,0.E+000,0.E+000,40.,30.;                         0000015P0000009
110,0.E+000,40.,30.,0.E+000,0.E+000,30.;                         0000017P0000010
144,21,1,0,23;                                                   0000019P0000011
108,1.,0.E+000,0.E+000,50.,0,50.,0.E+000,0.E+000,0.E+000;        0000021P0000012
142,0,21,0,25,2;                                                 0000023P0000013
102,4,27,29,31,33;                                               0000025P0000014
110,50.,0.E+000,30.,50.,0.E+000,0.E+000;                         0000027P0000015
110,50.,0.E+000,0.E+000,50.,40.,0.E+000;                         0000029P0000016
110,50.,40.,0.E+000,50.,40.,30.;                                 0000031P0000017
110,50.,40.,30.,50.,0.E+000,30.;                                 0000033P0000018
144,37,1,0,39;                                                   0000035P0000019
108,0.E+000,1.,0.E+000,0.E+000,0,0.E+000,0.E+000,0.E+000,        0000037P0000020
0.E+000;                                                         0000037P0000021
142,0,37,0,41,2;                                                 0000039P0000022
102,4,43,45,47,49;                                               0000041P0000023
110,50.,0.E+000,0.E+000,0.E+000,0.E+000,0.E+000;                 0000043P0000024
110,0.E+000,0.E+000,0.E+000,0.E+000,0.E+000,30.;                 0000045P0000025
110,0.E+000,0.E+000,30.,50.,0.E+000,30.;                         0000047P0000026
110,50.,0.E+000,30.,50.,0.E+000,0.E+000;                         0000049P0000027
144,53,1,0,55;                                                   0000051P0000028
108,0.E+000,1.,0.E+000,40.,0,0.E+000,40.,0.E+000,0.E+000;        0000053P0000029
142,0,53,0,57,2;                                                 0000055P0000030
102,4,59,61,63,65;                                               0000057P0000031
110,50.,40.,0.E+000,0.E+000,40.,0.E+000;                         0000059P0000032
110,0.E+000,40.,0.E+000,0.E+000,40.,30.;                         0000061P0000033
110,0.E+000,40.,30.,50.,40.,30.;                                 0000063P0000034
110,50.,40.,30.,50.,40.,0.E+000;                                 0000065P0000035
144,69,1,0,71;                                                   0000067P0000036
108,0.E+000,0.E+000,1.,0.E+000,0,0.E+000,0.E+000,0.E+000,        0000069P0000037
0.E+000;                                                         0000069P0000038
142,0,69,0,73,2;                                                 0000071P0000039
102,4,75,77,79,81;                                               0000073P0000040
110,0.E+000,40.,0.E+000,0.E+000,0.E+000,0.E+000;                 0000075P0000041
110,0.E+000,0.E+000,0.E+000,50.,0.E+000,0.E+000;                 0000077P0000042
110,50.,0.E+000,0.E+000,50.,40.,0.E+000;                         0000079P0000043
110,50.,40.,0.E+000,0.E+000,40.,0.E+000;                         0000081P0000044
144,85,1,0,87;                                                   0000083P0000045
108,0.E+000,0.E+000,1.,30.,0,0.E+000,0.E+000,30.,0.E+000;        0000085P0000046
142,0,85,0,89,2;                                                 0000087P0000047
102,4,91,93,95,97;                                               0000089P0000048
110,0.E+000,40.,30.,0.E+000,0.E+000,30.;                         0000091P0000049
110,0.E+000,0.E+000,30.,50.,0.E+000,30.;                         0000093P0000050
110,50.,0.E+000,30.,50.,40.,30.;                                 0000095P0000051
110,50.,40.,30.,0.E+000,40.,30.;                                 0000097P0000052
S      1G      4D     98P     52                                        T0000001
402
     402       1       0       0       0       0       0       000000000D0000001
     402       0       0       1       1                               0D0000002
402,6,3,19,35,51,67,83;                                          0000001P0000001

Form Number        1
Number of entries  6
Pointer to the DE  3 19 35 51 67 83

16 行（8 レコード）x 6 個のデータから成る．
一部 Parameter Line Count が 2 のものあり（108 の幾つか）．
144 108 142 102 と 110 が 4 つ．

110 は一つの面の直線か？	(以下は見やすい様に成型)
110,    0 ,  0 , 30 ,	0 ,  0 ,  0 ;                            0000011P0000007
110,    0 ,  0 ,  0 ,	0 , 40 ,  0 ;                            0000013P0000008
110,    0 , 40 ,  0 ,	0 , 40 , 30 ;                            0000015P0000009
110,    0 , 40 , 30 ,	0 ,  0 , 30 ;                            0000017P0000010
　x が 0 の，YZ 平面に平行な面の直線？

102 Composite Curve
     102       6       0       0       0       0       0       000010000D0000009
     102       0       0       1       0                               0D0000010
102,  4 ,   11 , 13 , 15 , 17 ;                                  0000009P0000006
　PD は，4 つの 110 を指している？
　直線を順に繋ぐと，面として表現できそう．時計回り？

108 Plane
     108       3       0       0       0       0       0       000010000D0000005
     108       0       0       2       0                               0D0000006
108,  1.,  0. ,  0. ,  0. ,    0 ,     0. ,  0. ,  0. ,          0000005P0000003
0. ;                                                             0000005P0000004
　Form Number が 0 ．Plane is unbounded. PTR shall be zero.
　平面の方程式？


142 Curve on a Parametric Surface
     142       5       0       0       0       0       0       000010500D0000007
     142       0       0       1       0                               0D0000008
142,   0 ,     5 ,   0 ,       9 ,     2 ;                       0000007P0000005


144 Trimmed (Parametric) Surface
     144       2       0       0       0       0       0       000020000D0000003
     144       0       0       1       0                               0D0000004
144,    5 ,    1  ,  0 ,  7 ;                                    0000003P0000002

     108       3       0       0       0       0       0       000010000D0000005
     108       0       0       2       0                               0D0000006
     108      12       0       0       0       0       0       000010000D0000021
     108       0       0       1       0                               0D0000022
     108      20       0       0       0       0       0       000010000D0000037
     108       0       0       2       0                               0D0000038
     108      29       0       0       0       0       0       000010000D0000053
     108       0       0       1       0                               0D0000054
     108      37       0       0       0       0       0       000010000D0000069
     108       0       0       2       0                               0D0000070
     108      46       0       0       0       0       0       000010000D0000085
     108       0       0       1       0                               0D0000086

108,    1.,  0.,  0.,  0.,     0,    0.,  0.,  0.,    0.;        0000005P0000003
108,    1.,  0.,  0., 50.,     0,   50.,  0.,  0.,    0.;        0000021P0000012
108,    0.,  1.,  0.,  0.,     0,    0.,  0.,  0.,    0.;        0000037P0000020
108,    0.,  1.,  0., 40.,     0,    0., 40.,  0.,    0.;        0000053P0000029
108,    0.,  0.,  1.,  0.,     0,    0.,  0.,  0.,    0.;        0000069P0000037
108,    0.,  0.,  1., 30.,     0,    0.,  0., 30.,    0.;        0000085P0000046

このデータの場合，Form は 0 ．
Form が 0 の場合，PD は A B C D PTR X Y Z SIZE ．
 Ax  +  By  +  Cz  =  D
1* 0 + 0* 0 + 0* 0 =  0
1*50 + 0* 0 + 0* 0 = 50
0* 0 + 1* 0 + 0* 0 =  0
0* 0 + 1*40 + 0* 0 = 40
0* 0 + 0* 0 + 1* 0 =  0
0* 0 + 0* 0 + 1*30 = 30