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 is an NBS publication. Order from: US Department Of Commerce, National Technical Information Service, Springfield, Virginia 22161 Sections

Section 3.9 - Parametric Spline Surface Entity (type 114)
Section 3.17 - Rational B-Spline Surface Entity (type 128)
Appendix E - Spline Curves and Surfaces
Appendix G - Colour Space Mappings


Example

A simple example IGES file (so you may recognise one when you see it) is shown below.
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