Switching from mm to m corrupts geometry - BUG

I noticed this problem when opening a rhino5 model in rhino6.
What should I do to avoid this?

Thank you!

Can you post the .3dm file with the geometry? Use the vertical arrow above where you type your message.

How far from the origin?

Your title talks about “switching from mm to m” but the text talks about opening a Rhino 5 model in Rhino 6. When and how did you change units? Did you simply open the Rhino 5 file in Rhino 6, or did you use Import or Insert?

area_test2_3.3dm (3.5 MB)

Hi David,
I uploaded the geometry. I saved it in Rhino6 format and I get the same problem.
In all cases I just opened the file, I haven’t used import nor insert.


The object is over 90 million millimeters from the origin which is probably the cause of the problem. Move the object close to the origin before changing the units from meters to millimeters and scaling. Then the geometry will be okay.


Ok, but this is quite a serious problem because most of architectural models are based on some geolocation. So the building has to stay 90million millimeters away from the origin in order to be properly aligned with the site. Even more, this problem didn’t happen in Rhino 5. That means that all the library that an office has will get corrupted when switching from R5 to R6.

Is there any solution besides moving the geometry?

Thank you!

Nope. There just aren’t enough digits available to the right of the decimal point when you use up so many on the left by being so far from the origin.

Hi John,
Yes, I understand, but this problem holds up the update from R5 to R6.
How was it possible in R5 and not in R6.

Thank you for your help!

I frequently work on geolocated architectural projects and very large infrastructure projects. We always create project local origins, which keeps the models within reasonable coordinate values. This works across Revit, AutoCAD, rhino, microstation, mx etc.

On a side note many other applications do have a way of declaring the geolocation of the models XYZ origin, so that the coordinates of model geometry do not become too large, and measurements can still be taken in reference to the ‘global’ coordinate system.

This does not remove the need distinguish between local and global coordinates, it just internalises the transformation inside the software.

@Bogdan_Chipara are you by chance opening models exported from another software in global/world coordinates? This is a problem opening models exported from Revit unless you export using local coordinates

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Hi dharman,

Thank you for solution regarding workflow on R6.
Still, this problem was not present in R5. And therefore, all the geometry from the library, which is in R5, will have a big problem when upgrading to R6.

Maybe there’s something else going on here.
The file you posted is a V6 file.
Please post a small V5 file that opens correctly in V5 but wrong in V6.
Hopefully, something like that isolated curve in your images.

Ok John, I uploaded the whole model. Thank you for looking into this!

area_test2_3.3dm (5.5 MB)

I really do not want the whole model.
Can you please open the file in V5, export that curve to it’s own V5 file and verify it is okay in V5 and wrong in V6?

@John, please check this model:
area_test2.3dm (803.3 KB)

It works well in r5 but not in r6 when converting from m to mm.
Thank you!

When you convert from meters to mm, I assume you are answering Yes to the scaling question?

I ask because the file you sent is already in mm.

I test on the file area_test2.3dm.

I open it with r5 and convert from mm to m and it works fine.
I open it with r6 and convert from mm to m and the geometry gets corrupted.

The problem persists on area_test2_3.3dm which is an R6 file.

@John_Brock, From mm to m, my mistake.

And are you answering Yes or No to the scaling question when you change the unit?
I’ll assume Yes as anything else would not make sense.


Thanks for the example and details

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On the file: area_test2.3dm,
Tested on R5 and R6 I say, yes, there is a problem when transforming from mm to m in R6 which doesn’t happen in R5.

Thank you for tracking this bug! It is a very big issue.

What about changing units without scaling and scale after

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@Javier, I like your workaround!

I scale after and I get this:

When I zoom the geometry is in some strange wireframe mode:

I hope your suggestion might help to solve this bug. Thanks.