General considerations in preserving data - with SketchUp/Layout Specific questions for discussion

Continuing the discussion from How to preserve Sketchup creations & keep them viewable indefinitely?:

I started this as a reply to the above linked thread, but as I wrote, I went off on a few tangents (stream of consciousness - that’s how my mind works!), so I thought it better to start a new thread. I’m also not happy about the title I’ve given, so suggestions - especially shorter ones - are welcome!

This caused me to do a bit of research. Long ago (at least 10 years) I’d heard that WORM (Write Once Read Many) disks were the most “stable” form of physical media. So I set out to update my knowledge.

While I didn’t find any current comparisons on the longevity of physical media (at least not ones that appeared either well researched or even well linked to source material), I did find a good, relative succinct and well written summary of the general long term data storage problem:

While it is over 4 years old, nothing written more recently contradicts the advice given therein, nor does it appear that any new solutions have appeared since.

What I find most intriguing - and perhaps problematical for we SketchUp and Layout users – is the recommendation to convert your data to open source formats, on the assumption that the ability to use data in open source formats is likely to continue beyond proprietary formats. – and to continue as hardware, software, and apps evolve. (last bit added by me as an assumption - it’s not explicit in the source I quoted!)

I’m thinking that there can be multiple purposes for archiving our models (and I don’t claim this list is exhaustive):

  • Simple desire to preserve a snapshot of your work. Doesn’t include an intention to be able to manipulate/change it a generation later. Think of this as a portfolio of your work.
  • As an updateable reference to something, most likely a real world something. For example: The Tiny Home on Wheels I’m still designing. Someday I’ll build it. I’ll want to preserve a record of how I designed it, but I’ll also want to preserve a model that I can use to keep a current “as built” model. Should I do a remodel a few years later, I’ll want to change the model to reflect the real world.

Almost all of the advice I found in my research was addressed at the hardware. What I’m worrying about is the software: Regardless of its intentions, there’s no guarantee that some form of SketchUp/Layout will endure to continue be able to access and manipulate our .skp/.layout files. Over generations, I tend to agree with the expectation that open source formats are a better bet than proprietary ones. Which brings me to the biggest question I have:

Which open source formats for CAD/CAM models are likely to last? And continue to have a means for manipulation? For that matter, is there even one now which can preserve the details we care about in our models in a way that we can be confident we can manipulate in 10-50 years?

I’m less worried about the documentation (Layout) side of things. No matter what happens on the CAD/CAM side of things, I’m fairly confident that construction documentation will be needed - and that there will always be a way to create construction documents from models. And I’m comfortable with long term preservation as PDF (which is the proprietary form I think most likely to endure) or image files (.jpg or .png)

I sort of fell into the whole CAD scene pretty much by accident through being asked to do more from work. I needed sure fire ways and confidence to produce more complicated designs, so I thought I’d get stuck into learning some CAD in my spare time.

I first started using a 2d CAD program that I could use really well quite quickly. I used it for a long time not really thinking I’d be able to use anything like these 3d modeling programs that I kept seeing. This program called SketchUp kept catching my eye and eventually I realised I could transform all my drawings into 3d quite easily and look cool at the same time. :grinning:

The only problem was, all my files were saved in a custom file format that the 2d program used, bummer! I didn’t want to continue with that program so to preserve everything I had done before, I had to open them up in the 2d software and export them as DWG, one at a time. There were just short of 800 I think, it took two evenings! But now I have all the originals in DWG I am pretty confident that format will last a long time if not forever, even though many of those are now redundant anyway. I think DXF is pretty solid too.

As for the future of SketchUp, from what I’ve seen I think Trimble have brought it on leaps and bounds since Google. The whole way they market the product and stay connected to the users through this forum and social media is really good I think. It’s not a perfect product, there is no such thing. I think it’s in a strong position, but with the concerned speculation of a web based Pro looming, I have a feeling that could change. (Just my opinion)

No! Open source (software) refers to implementations. A file format is no implementation, but a specification (without source code) of which can exist multiple implementations. So you rather mean open standards. The focus is on standard, because it does not prescribe anything about the type of software that implements it (and about the ideology of open/closed source, there are of course also analogous ideologies about open standards…).

There are quite a lot of open standards that come and go (Who still uses .vrml?; Even Collada seems to be replaced by glTF) and it is questionable whether they are intrinsically better than proprietary formats (like with open/closed source software).

There is however one advantage. It is not that open standards are any likely to last longer (but they can get momentum if backed by multiple companies). It is that if accurately documented, (and if you have programming skills or pay someone who has) they can theoretically be re-implemented and revived at any time in the future. In contrast, there exists (and can exist) only a single implementation for the .skp format, and you rely on that software still being usable.

Any conversion comes with some loss if the data models of both formats do not have an unambiguous mapping between features. Especially, application-specific formats (like .skp or .psd) are designed to represent all specific features of this application.
In case of my post in the linked discussion, I suggest a conversion in addition to preserving the data in the original (feature-complete) file format.

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Absolutely correct! I should, indeed, have used “open standards” instead of “open source”. I’m choosing not to edit my original post so that your quote of me will still make sense.


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