Hi Janne, yes IGES files will take a lot longer to process, they only contain individual surfaces and so MoI has to do some more work to join those surfaces together to try and make a solid out of it.

There is also other various overhead in loading an IGES file as compared to a 3DM file, so it's not something you want to use as your primary file format for storing objects, you should only really use IGES for transfer of data between different programs, not as the main storage format. For MoI you should instead use 3DM files as the primary format for your regular saved work.


> but what should i do with my 170 mb file. it's saved as iges and i can't load it with moi know.
> but i need it.

You can try turning off the automatic joining, that may be where things are getting hung up. Especially if there are many different solids with pieces touching each other that can make for quite complex joining operations.

You can turn off automatic joining for IGES imports under Options > Import/Export > IGES options > "Join surfaces on import".

But it's also not that good to have just a huge pile of surfaces - basically by saving only out to IGES format you've kind of lost some amount of information because the IGES file does not have the connection information between surfaces in it anymore. It's really not a good format to use for your main data save because of that, only use it for transfer between programs.

- Michael