are you using Teamcenter or using Vis mock up? If so you can use this data to do an overlay compare of two different revision against each other to verify changes. I am sure there are other reasons, but this is what we mainly use it for.
We use it to generate (team-center Dispatcher) our PDF's in the Release process. It is much faster to create a pdf from a cgm than having to open the drawing in NX and generate it.
Ronald van den Broek
Senior Application Engineer
Winterthur Gas & Diesel Ltd
NX9 / TC10.1.2
Building new PLM environment from Scratch using NX11 / TC11
There is also a "track changes" command in native NX that will compare the previous drawing to the current drawing. It saves some CGM data to do the comparisons, but I don't know if it is directly related to the "save CGM data" save option.
Yes, I thought the same, that it will be usefull to track changes. But I saved the drawing with this option enabled. After that, I tried to use the command "Track Drawing Overlay" and also "Visual Overlay", but the next message appears: "No snapshot data exists in the current drawing file. Select the Create Snapshot Data option to create snapshot data."
Therefore, I create the requested snapshot data. When I click "Create Overlay Data" I see in the Status Line: "Writing CGM"