Very large file size after attachGHSData

Hi Everyone,

I am working on a ship project and I am attaching GHS data to tanks and compartments. After having attached such data to some (I think it was 6 or 7) closed polysurfaces I save the Rhino file and it jumped from about 15MB before the attachGHSData step to some 300MB. I now have 35 closed polysurfaces with GHS data attached and the saved Rhino file is 2GB large.

There’s another 90 compartments to go and I expect I will very soon get problems due to the huge file size.

Is this normal or is there a way to keep the file size within reasonable limits?

Happy to give any other required information to help answer this question, not sure at the moment what that would be.

All the best for now.


This is not normal. AttachGHSData needs meshes for the polysurfaces in order to compute results. If you Save Small, does the file size go down?

Yes it does. 2.5GB down to 12.3MB. Nice! Thanks for that idea.

I can work with that solution. But I guess it’s a work-around and also out of curiosity: Do you see something going wrong that might be worth sorting out?

There must be some geometry in your model that is causing the mesher to generate massive meshes. Is your geometry extremely complicated? I would assume that your file size would also jump up this much if you viewed your model in shaded mode and then saved.

It is a complex model, but I would not say it’s extremely complicated.

When I save it in shaded mode without the GHS data the file size goes from 12.3MB to 14.5MB.

Opening the model which I saved with “save small” is fast as usual. When I then save the model as a GF-file Rhino starts to create all the required meshes for the different compartments which I prepared GHS data for and this takes several minutes.

Not sure why this is happening, when I have the time I’ll try the process on a different model to check if the same happens there.

I think the AttachGHSData command is generating much higher precision meshes than what is used for display. These meshes are recreated if they are missing, so save small will work fine for this model.