Purging and Deleting Redundant Elements

Looking to make sure that my Rhino projects are devoid of unnecessary elements.

On AutoCAD versions for many years, a project retained every deleted and purged item or drawing that was ever imported into it. This included items deleted from project space, block lists and inserted drawings, even those which had been purged. As I recall there was another level of deletion required even after purging to truly get rid of obsolete elements in a project’s database. Purging only removed them from the lists, but not from the project. This was a particular issue when a new CAD project began life as new copy of other projects in order to take advantage of a particular projects’ layer structure. CAD projects which started several building projects earlier began to accumulate elements from all previous projects hidden in their databases and became huge.

I’m looking to ensure this doesn’t happen in Rhino.

You can use “Save small” or “only geometry” when saving your file

Thaks Ivelin, but I believe save small only eliminates views generated to display in GUI view windows from the save to accelerate save time and decrease file size. (Such a file takes more time to open because it has to regenerate those views.) I know that it faithfully saves everything else; I use it for every save.

Not looking to save “only geometry” and nothing else. In fact I want to keep everything in use in a project.

I want to make sure that elements apparently deleted from a project truly are deleted and not hanging around as unreferenced elements contributing to file size and save/open time.

What kind of background data do you want to delete?

This is what purge can remove from the file, is that not enough?

That’s my question. It wasn’t enough in AutoCAD. They were still there taking up space and slowing down projects.

All purge did was remove them from the list of available definitions, styles, groups, patterns, layers, etc. Not such a big issue on some of these elements, but if large drawings had been inserted as blocks, after being purged they became orphanned embedded data, eventually making a project huge but not showing up on the list of blocks. It could become a big problem. There was another command required to clean the database of these elements, but I don’t recall it.

I’m confused. :thinking:

Are you importing into Rhino from AutoCAD or importing in AutoCAD after purging in Rhino?

I’m not using AutoCAD. But needing to ensure that Rhino, which functions like AutoCAD in very many ways, doesn’t - like AutoCAD - need something more than purging to truly remove something from the database as opposed to just removing it from the list of available items. If it does work that way, I’ll need to know how to truly get rid of something.

So all that was hypothetical?
No wonder of my confusion.

I need to know if Rhino requires more than purging to remove things from projects, and if so what the method is. Never asked the question of AutoCAD, and that led to trouble, so I’m asking it here.

Purge will remove most of the obvious stuff, but not all. Things that might get “stuck” and not removed by Purge are plug-in data, bitmaps used by previously inserted Picture elements that have been deleted, and some materials (although Purge is supposed to work on those). Running Audit3dm on a file and looking at the different tables and their size might give you an idea if anything is stuck in there.

Thanks Helvetosaur.

2 questions arise for this string to help with:

  1. Once Audit is run (I think the AutoCAD command had a similair name) we’ll need a way to remove the stuck elements, so I hope we learn that here.

  2. Maybe there’s a way to proceed with project duplicates that doesn’t accumulate so many elements. Maybe if any project is saved in some special way (as a template, perhaps?) it wouldn’t save anything previously deleted or purged.

Hello - Rhino files, once closed and reopened, should not contain any geometry, groups, layers or materials that have been deleted in a previous session and the file saved.


Thanks H’saur and Pascal

If we can resolve an apparent descrepancy here, it’d be great. I had Auto CAD files once where this caused a large project to grind to a halt. I’d like to anticipate any such event long before it happens.

Pascal, what about the other elements? Blocks, inserted drawings, materials, and other purgeable items.

For plug-in data, there is a checkbox to save that or not when you run _SaveAs. For bitmaps, I think maybe I might have been wrong there as bitmaps are no longer stored in the file…? @pascal

The main concern here is about blocks, I guess, as they can get big. Also drawings inserted as updatable elements.

Hi Mitch - Textures (including Picture) are saved by default with the file, but it’s controlled by the SaveTextures thing on the Save dialog or the command line for -SaveAs etc. But BackgroundBitmaps are stored in the file. I do not think anything else is any more.