Rhino 6 reading Rhino 7 Files

The preview is an embedded PNG file in a well-known location in the file. All older file previewers can preview new file images - but that’s a far cry from reading the data. They can also read the version number in the file, and the notes. We don’t change that part near the top of the file. The file format was designed to be extendable as Rhino grew and changed. Some changes that we’ve added over time that can’t be understood by previous versions of Rhino include:

  • Improvements to annotations and their representation
  • SubD objects
  • Double-precision mesh vertices
  • PBR materials
  • Enhanced and user-customizable user-data

It’s impossible for us to build a file format that lets you save a SubD object in the model, open it in Rhino 5 (which doesn’t know anything about SubD) and not destroy your work when you save. The file versioning is designed primarily to make it so you don’t accidentally destroy your own work when saving between versions.

I understand that saving as old versions (something we work very hard to make work properly so that you have very high-fidelity conversion when working with older versions of Rhino) looks selfish. I might argue that the fundamental “evil” move is to not have any mechanism to save out to older versions. I think that’s where the lock-in begins.

Oh, and all our file reading tools are open-source. So if you need data from any of these files, a talented programmer can get at the data. That’s not true of other products that lock you in.

The difference is that you get a choice. You can use whatever version of Rhino you want for as long as you want. You can use Rhino 4 until 2035, if you can find a version of Windows that will run it well, on a very low-res screen. If the changes we make to Rhino don’t delight you, please don’t upgrade. We don’t want your money just because there’s a new number on the splash screen.

If there’s not value in being able to read, write, and create Rhino 7 files - including all the new SubD and material information in them - then you don’t need it. There’s not a high-fidelity automatic backward conversion that doesn’t destroy data. That’s why we leave it as a choice for the model creator to decide how to save. If a V6 file is good enough for the data they care about, then they can save it that way and send it to people who use that version.


A stand-alone utility to convert R7 to R6 (and earlier versions?) would go a long way toward relieving the pain of exchanging files on this forum. Each person could do it on their own without having to beg R7 folks to save as R6.

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Wait, wait… Let´s get this thing straight here. I am not perceiving or projecting any evil here. In fact I am a huge fan boy. Love the product. Love the community. Love the team. Recommending it up and down. In my second comment I am just guessing. In fact I admit that. And your explanation is pretty enlightening and I thank you for it. I thought that SubD ought to be a reason on my way home.

And when we talk about the money… It´s not my money. It´s my bosses money. I guess you can imagine what it takes for an employee to convince people who are grounded in their old tools to consider migration, budget and investment, right? Not an easy thing to do. And maybe I sense a bit of condescending tone. And if this is indeed the case, trust me, I am far from the kind of a person to treat like a dog. But maybe I am misreading your tone.

In fact, in my use of the program so far, this is the only inconvenience I have faced. That I have to contact back clients to tell them to save the files in a previous version (and usually is mostly simpler geometry). The only real issue is that usually for the time they respond I am usually done with the task at hand. Not the end of the world. But if there was some way to convert the file on your web page or my account page this will be absolutely great. I am not gonna use the new features. And a disclaimer for possible data corruption would be enough. It will just go a long long way if it ever happens. I can’t know the particular cases of your other clients. But our prospects are that we will most probably wait for R8. Again, not the end of the world.

All that being said, keep the great work. For me this is the best product on the market.

I’m sorry for projecting a condescending tone. That wasn’t my intention. What I was hoping to convey is that I want you to be in full control of what you choose to do. I want you to judge our contribution to your work, and only pay us if we’re doing something useful. We don’t want you locked in, and we don’t want you resenting that you’re locked in!

I’m thrilled that you’re so happy with Rhino, and I hope we can keep it that way by continuing to make tools that make you want to upgrade.


Yeah, I hear you. Another possibility is that the conversion utility makes files that (as they must) have data missing. And then people answer questions based on bad information. I think that people who support customers on this forum owe it to the people they’re answering to be on the same version of Rhino, or simply choose to not answer. It’s not their fault that others choose to stay on an older version of Rhino.

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Ouch! I’m not sure you heard me at all. A proper file conversion utility would either warn or fail if an R7 file has geometry that can’t be converted to R6.

I choose to stay on R6 because the price of upgrading to R7 is not worth it to me, especially since most of my use of Grasshopper is to offer free support to McNeel customers on this forum. To suggest that I not even ask politely for an R6 version of an R7 .3dm file is frankly rude. It’s also a disservice to new R7 users who don’t know any better and counterproductive to McNeel’s own interest.

Yeah, that’s hard to do well. It’s not going to be a priority for us anytime soon.

Thanks for supporting people. You’re welcome to ask for an old file, of course. But posting old versions of a file should not be a precursor to getting support for our currently shipping product. Please know that I have no expectation that you’d be able to support Rhino 7 users when your only vantage point is Rhino 6.

One year old. You don’t understand.

Mia culpa. Please replace all instances of “old” with “previous version”.

R7 started “shipping” (became official) less than two months ago, yet R6 is already old to you.

Obviously you expect everyone on this forum to upgrade immediately and didn’t anticipate the chaos that would ensue from mixing new R7 users with “old” R6 unpaid support volunteers. That careless attitude takes a lot of the fun out of it for me.

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Wonderful little magician :black_heart: :black_heart: :black_heart:

I´ve ran a few tests. Can confirm that some of the new annotations don´t convert right. But most of the geometry is fine. More than enough for me.

  1. Has this utility (and the person who wrote it) been vetted by McNeel?

  2. Can we be sure it contains no malware?

  3. Why didn’t McNeel produce such a utility of their own?

Prioritization. The same could be (and has been) asked of zillions of potential projects. We’re not infinitely capable, and so we make choices about what to do, and when. As you can see from David’s explorations, the simple solution doesn’t get all the right answers.

In many cases, we need the full power of Rhino to be able to do geometry conversions (for example, SubD to NURBS or mesh). That’s not something we give away for free, and so it won’t be in any free file converter.

The expectations of file converters are high - everyone (including me) would expect 100% fidelity, and a robust report of when that expectation wasn’t met. It turns out that’s a non-trivial project.


I remember installing Pancake because it was claimed to resolve some differences between R5 and R6 but it did nothing for me, so I’m reluctant about this one. Would rather it come from McNeel.

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I can confirm I can see these limitations right now. The good thing for me is that at least for non-complex quick conversions there is already a way. Official or not. I do get Joseph arguments though. This little tool I believe is open, so maybe the community can in time improve it a bit to what is technically possible. Still a good development. But one should really know that there are indeed limitations.

Yep… And I don’t see why the 7 format has no backwards compability. The fact that AutoDesk are resorting to this kind of tactics doesn’t mean that they are worth copying…
Model 1_V6.3dm (12.1 MB)


WRONG McNeel continues to only charge for major upgrades (V6 to V7) which are not annual

Factually correct. In my case, last year I’ve made my company purchase like 6 licenses or so… So for me in particular is kind of anual. Then the WIP for Rhino 8 is ongoing right now and I guess it will be finished by 2022… So…

Close enough. R7 became official only a year after I upgraded to R6 and more major upgrades are on the horizon, including the fabled GH2.

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Do you mean previous versions of Rhino cannot open V7 format files? Do you mean that earlier versions of Rhino cannot open V7 files. Versions of Rhino has never been able to open files saved in subsequent formats. I’m not aware of any software which can open files saved in the later formats.

Rhino V7 can save files in format going back to Rhino V2 format.