IGES Export Error?

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1

Cad file formats are completely new to me but I am trying to learn the IGES file format. I exported a simple cylinder from Shapr3D as IGES.

cyl.shapr (4.3 KB)

As I read through the spec and compare that to the IGES file produced by Shapr3d something does not look correct. Either Shapr3D has a bug or I misunderstand how Hollerith format works (which is very possible, I am no FORTRAN expert):

This is the Global Section from the IGES file:

1H,,1H;,89H/var/folders/cg/xpwdhpv9635ctpsvh4w5rl900000gn/T/4204B791-548G      1
9-43AB-8ACF-5920E0F3EA0E.tmp,67H/var/folders/cg/xpwdhpv9635ctpsvh4w5rl90G      2
0000gn/T/export/temp_export,7HShapr3D,3H3.0,32,24,8,56,15,89H/var/folderG      3
s/cg/xpwdhpv9635ctpsvh4w5rl900000gn/T/4204B791-5489-43AB-8ACF-5920E0F3EAG      4
0E.tmp,1.,2,2HMM,1000,1.,13H210309.191307,1D-05,1000000.,,,9,0,13H210309G      5
.191307;                                                                G      6

As a concrete example of the issue, shouldn’t:

89H/var/folders/cg/xpwdhpv9635ctpsvh4w5rl900000gn/T/4204B791-548G 1 9-43AB-8ACF-5920E0F3EA0E.tmp

be encoded like this instead?

98H/var/folders/cg/xpwdhpv9635ctpsvh4w5rl900000gn/T/4204B791-548G 1 9-43AB-8ACF-5920E0F3EA0E.tmp

I believe all the length values are reversed (or something). I expect a “strict” IGES parser will blow up on that and has a big potential for data frame alignment issues if the values are actually parsed.

This is another export from iPad version:

1H,,1H;,129H/private/var/mobile/Containers/Data/Application/74E1F485-0FAG      1
9-4366-BC85-7F9A102E31C7/tmp/45F0381F-3B85-4A03-9D9E-BB53A645FBEB.tmp,  G      2
107H/private/var/mobile/Containers/Data/Application/74E1F485-0FA9-4366-BG      3
C85-7F9A102E31C7/tmp/export/temp_export,7HShapr3D,3H3.0,32,24,8,56,15,  G      4
129H/private/var/mobile/Containers/Data/Application/74E1F485-0FA9-4366-BG      5
C85-7F9A102E31C7/tmp/45F0381F-3B85-4A03-9D9E-BB53A645FBEB.tmp,1.,2,2HMM,G      6
1000,1.,13H210309.213201,1D-05,1000000.,,,9,0,13H210309.213201;         G      7

129H/private/var/mobile/Containers/Data/Application/74E1F485-0FAG 1 9-4366-BC85-7F9A102E31C7/tmp/45F0381F-3B85-4A03-9D9E-BB53A645FBEB.tmp

should be

138H/private/var/mobile/Containers/Data/Application/74E1F485-0FAG 1 9-4366-BC85-7F9A102E31C7/tmp/45F0381F-3B85-4A03-9D9E-BB53A645FBEB.tmp

2

Thanks, we will look into this.

3

The file seems correct, because the part G 1 is not part of the content (just formatting). For example
/var/folders/cg/xpwdhpv9635ctpsvh4w5rl900000gn/T/4204B791-5489-43AB-8ACF-5920E0F3EA0E.tmp has exactly 89 characters.

4

Oh, I did not remove the framing before counting! you are right. Sorry for the false alarm