Important! Pre-Process IGES Settings

[US_Helpdesk]

Starting in 3.4 an option was added in Preferences to Pre-Process IGES models on import. This option forced import of IGES by a 3rd party CAD importer that improves models with trimming issues. We've recently discovered an issue where 2D features such as Circles and Slots may have rounding errors when this option was used on CAD import.

Please modify the following file if you are using the Preference>Import>Pre-Process IGES Using ACIS Importer

C:\ProgramData\Nikon\CMM-Manager 3.4 SP1\Options\IGES.txt

Add a line to this file:

"TrimCurveReadPreference=2"

Then Save file.

Note: If problems occur when picking round (cylinder, sphere, cone, etc.) features try changing the SplitPeriodic setting from False to True.

"SplitPeriodic=True"

[ragin1]

This setting was selected for me during the install. I have not touched it, I don't understand it. I did not have any problems using .step or .iges files in 3.3. From 3.4 I have had problems with numerous cad files, .step and .iges, not showing 2d circles, or their cylindrical interior. Every cad guy I have worked with for the last 20 yrs has complained about .iges files. I used them a lot with PCDMIS. I don't remember having many problems with them.

Based on the many derogatory comments I heard over the years about .iges files, and the availability of many of our current parts in .step format, I tried to get my guy to provide .step when possible. Then in 3.4 we began to have the problem mentioned above with the .step files.

When I noticed the export options you provided for .iges files, I converted a few of the "problem" files with those settings. It helped. The 2d holes became available. Was the TrimCurveReadPreference my root problem, or the export setting of the cad file created by Master Cam and/or Solid Works?

[US_Helpdesk]

It was likely the export settings on the CAD system. One note... The Step import in 3.3 was not a problem, this is new to 3.4. The IGES options file modification mentioned above also effects STEP import since IGES is used as an intermediary format.

I would suggest making this change if you're using STEP or IGES import, especially if the Preference is checked as mentioned in the first post.

[mcasey]

Is this only for 3.4 or does the same issue exist in 3.5?

[US_Helpdesk]

This is resolved in 3.5 since we've made the default settings for IGES Options file according to what's mentioned here.

[Lucky_Jasper]

I am running 3.4 SP1 and there is no options folder. Do I need to add this folder and file? See Attachment

[US_Helpdesk]

Please note file path... It is ProgramData (not Program Files)

i.e. - C:\ProgramData\Nikon\CMM-Manager 3.4 SP1\Options\IGES.txt