# How can I include seperate Slicing Parameters in my 3mf file

I am trying to write a program that edits a 3mf file by defines different slicing parameters for different stls that I have previously merged into my 3mf file, but I am a little bit confused about the configuration of the 3mf file, and where I would look to make changes in the slicing parameters. Can anyone lead me in the right direction as to where I could look? I'm assuming that I wouldn't be making any changes to the .model file because it seems like it only holds information about the meshes.

Thanks and let me know if it would be helpful for me to clarify anything.

Huh. On a hunch I just changed a copy of a .3mf model to have a .zip file extension, and what do you know, it works! 3mf is just a set of compressed xml.

The zip folder structure I saw included a MetaData folder. I bet you could put just about anything you wanted in there, as long as it doesn't conflict with things other 3mf parsers are expecting to find.

I tested this. I dumped an unrelated pdf file into the folder and re-zipped it. Both MS 3D Builder and Cura were able to open the updated file just fine. However, saving the file again in 3D Builder did not preserve the PDF.

I suppose there's a lesson here, too: we may need to be wary of models we download off the internet. They could include literally anything.

This also raises an interesting possibility: password protected 3mf files. If 3mf is just a zip container, and zip files can have passwords, it follows logically that 3mf files can have passwords.

• I suppose there's a lesson here, too: we may need to be wary of models we download off the internet. They could include literally anything. Apr 8, 2020 at 21:56
• wel 3mf could, but not a pure STL - try opening those and you get garbage... Apr 9, 2020 at 5:49
• I think stls just store a series of coordinates describing polygons. You can easily read/write to it but the flaw of the 3mf is that it is simply a zipped file, but having multiple files inside the 3mf allows it to store more information. Apr 9, 2020 at 6:46