IGES

Notes by Paul Bourke


IGES stands for Initial Graphics Exchange Specification and was written by a panel for the National Bureau of Standards. The strongest argument for IGES is its high level of support by CAD packages running on the larger computer systems. IGES is both a 2D and 3D format.

IGES.pdf

Example

A simple example IGES file (so you may recognise one when you see it) is shown below. Each line is based upon a 80 character string, from the era of 80 character punch card readers from the computers of the 70's and 80's running early versions of FORTRAN. Data containing text strings are stored in so called "Hollerith" format, that is a number which is the length of the string, followed by an "H", followed by the string itself. For example the line after the header line below is: ", ; box+line.IGS box+line.IGS CGT v1.0 IGES 3.0 16 8 24 8".

The character in column 73 determines the type of data on the line, this may be S, G, D, P, or T standing for Start, Global, Directory Entry, Parameter Data, and Terminate.

IGES Start section created by Claris Graphics Translator v1.0           S      1
1H,,1H;,12Hbox+line.IGS,12Hbox+line.IGS,8HCGT v1.0,8HIGES 3.0,16,8,24,8,G      1
24,12Hbox+line.IGS,1.0,1,4HINCH,32000,1.6,13H910305.183439,,,3HIBB,3HWCPG      2
,4,0;                                                                   G      3
     124       1       1       0       0       0       0       0 0 0 0 0D      1
     124       0       0       1       0       0       0                D      2
     124       2       1       0       0       0       0       0 0 1 1 0D      3
     124       0       0       1       0       0       0                D      4
     410       3       1       1       0       0       3       0 0 2 2 0D      5
     410       0       0       1       0       0       0                D      6
     124       4       1       0       0       0       0       0 0 0 0 0D      7
     124       0       0       1       0       0       0                D      8
     124       5       1       0       0       0       0       0 0 1 1 0D      9
     124       0       0       1       0       0       0                D     10
     410       6       1       1       0       0       9       0 0 2 2 0D     11
     410       0       0       1       0       0       0                D     12
     124       7       1       0       0       0       0       0 0 0 0 0D     13
     124       0       0       1       0       0       0                D     14
     124       8       1       0       0       0       0       0 0 1 1 0D     15
     124       0       0       1       0       0       0                D     16
     410       9       1       1       0       0      15       0 0 2 2 0D     17
     410       0       0       1       0       0       0                D     18
     124      10       1       0       0       0       0       0 0 0 0 0D     19
     124       0       0       1       0       0       0                D     20
     124      11       1       0       0       0       0       0 0 1 1 0D     21
     124       0       0       1       0       0       0                D     22
     410      12       1       1       0       0      21       0 0 2 2 0D     23
     410       0       0       1       0       0       0                D     24
     124      13       1       0       0       0       0       0 0 0 0 0D     25
     124       0       0       1       0       0       0                D     26
     124      14       1       0       0       0       0       0 0 1 1 0D     27
     124       0       0       1       0       0       0                D     28
     410      15       1       1       0       0      27       0 0 2 2 0D     29
     410       0       0       1       0       0       0                D     30
     124      16       1       0       0       0       0       0 0 0 0 0D     31
     124       0       0       1       0       0       0                D     32
     124      17       1       0       0       0       0       0 0 1 1 0D     33
     124       0       0       1       0       0       0                D     34
     410      18       1       1       0       0      33       0 0 2 2 0D     35
     410       0       0       1       0       0       0                D     36
     124      19       1       0       0       0       0       0 0 0 0 0D     37
     124       0       0       1       0       0       0                D     38
     124      20       1       0       0       0       0       0 0 1 1 0D     39
     124       0       0       1       0       0       0                D     40
     410      21       1       1       0       0      39       0 0 2 2 0D     41
     410       0       0       1       0       0       0                D     42
     304      22       1       1       0       0       0       0 0 1 0 0D     43
     304       0       0       1       2       0       0                D     44
     304      23       1       1       0       0       0       0 0 1 0 0D     45
     304       0       0       1       2       0       0                D     46
     304      24       1       1       0       0       0       0 0 1 0 0D     47
     304       0       0       2       2       0       0                D     48
     304      26       1       1       0       0       0       0 0 1 0 0D     49
     304       0       0       1       2       0       0                D     50
     304      27       1       1       0       0       0       0 0 1 0 0D     51
     304       0       0       1       2       0       0                D     52
     304      28       1       1       0       0       0       0 0 1 0 0D     53
     304       0       0       1       2       0       0                D     54
     110      29       1       1       1       5       1       0 0 0 0 0D     55
     110      78       1       1       0       0       0                D     56
     110      30       1       1       1       5       1       0 0 0 0 0D     57
     110      78       1       1       0       0       0                D     58
     110      31       1       1       1       5       1       0 0 0 0 0D     59
     110      78       1       1       0       0       0                D     60
     110      32       1       1       1       5       1       0 0 0 0 0D     61
     110      78       1       1       0       0       0                D     62
     110      33       1       1       1       5       1       0 0 0 0 0D     63
     110      78       1       1       0       0       0                D     64
     212      34       1       1       1      41      37       0 0 0 0 0D     65
     212       0       1       2       0       0       0                D     66
     406      36       1       0       0       0       0       0 0 1 2 0D     67
     406       0       0       1      16       0       0                D     68
     404      37       1       0       0       0       0       0 0 0 2 0D     69
     404       0       0       2       0       0       0                D     70
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                   1P      1
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                   3P      2
410,2,1.0,0,0,0,0,0,0,0;                                               5P      3
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                   7P      4
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                   9P      5
410,3,1.0,0,0,0,0,0,0,0;                                              11P      6
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  13P      7
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  15P      8
410,4,2.0833333E-2,0,0,0,0,0,0,0;                                     17P      9
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  19P     10
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  21P     11
410,5,1.9999999E-2,0,0,0,0,0,0,0;                                     23P     12
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  25P     13
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  27P     14
410,6,2.0,0,0,0,0,0,0,0;                                              29P     15
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  31P     16
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  33P     17
410,7,1.0,0,0,0,0,0,0,0;                                              35P     18
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  37P     19
124,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0;                  39P     20
410,8,1.0,0,0,0,0,0,0,0;                                              41P     21
304,2,1.25E-1,4.1666667E-2,1H2;                                       43P     22
304,4,1.0,6.9444447E-2,1.25E-1,6.9444447E-2,1HA;                      45P     23
304,6,1.0,6.9444447E-2,1.25E-1,6.9444447E-2,1.25E-1,                  47P     24
6.9444447E-2,2H2A;                                                    47P     25
304,2,1.25E-1,1.25E-1,1H2;                                            49P     26
304,2,6.9444447E-2,5.5555555E-2,1H2;                                  51P     27
304,2,2.5E-1,6.9444447E-2,1H2;                                        53P     28
110,1.125,9.375,0.0,3.25,9.375,0.0;                                   55P     29
110,3.25,9.375,0.0,3.25,8.375,0.0;                                    57P     30
110,3.25,8.375,0.0,1.125,8.375,0.0;                                   59P     31
110,1.125,8.375,0.0,1.125,9.375,0.0;                                  61P     32
110,1.25,8.25,0.0,3.625,8.875,0.0;                                    63P     33
212,1,12,1.0555555,1.6666667E-1,1,1.5707963,0.0,0,0,1.3888888,        65P     34
8.875,0.0,12Hbox and line;                                            65P     35
406,2,8.0,1.05E1;                                                     67P     36
404,7,5,0.0,0.0,11,0.0,0.0,17,0.0,0.0,23,0.0,0.0,29,0.0,0.0,35,       69P     37
0.0,0.0,41,0.0,0.0,0,0,1,67;                                          69P     38
S      1G      3D     70P     38                                        T      1