Invisible Block issue


I have run into an odd situation that I need to find a fix for - I have opened a couple of autocad DWGs in rhino, and blocks are somehow not there but they are.

Some of the drawing is there, some of the blocks are there, but some are not visible - they are not hidden, all the layers are switched on, they are not selectable by selecting block instances or selall, just a blank space where the thing I have been asked to model should be…

However, if I open the block manager, they are in there - still not selectable from the block manager, but they can be exported.

If I open the file of the exported block - everything is there as normal, so the information is there, it’s in the drawing, the block is there in the block manager… it’s just … not there, in any practical sense.

I have only noticed this since the last update - 25 I think.

Unfortunately I can’t include any files as it is work related stuff under NDA, and I have no idea how I would go about recreating the issue with generic data.

If anyone knows a fix or work around for this, that would be very helpful, thank you.

Hi Peter -

Changes in the Rhino 7 code are rare these days, and are all related to fixing severe crashes or regressions.

Apart from that, we need to be able to reproduce something to be able to fix it, and I don’t know where to start looking from your description alone.

Thank you Wim,

I only mentioned the update as I have not noticed this issue before this week after updating rhino, if it has happened before it has been with something that I was not working on and did not notice.

This has happened with 2 different autocad drawings from 2 different companies last week, both times the ghost block has been the one thing in the drawing that I have been asked to model, which isn’t very helpful. It is visible and present in autocad, but vanishes when importing the dwg into Rhino.

I have exported the block from one of the drawings, changed the info, created a new block with the same name, pasted that new block into the original file to replace the old one, deleted everything else from the file.

Now there is a rhino file with nothing in it, but the block is visible in the block manager with a count of 0, not selectable, but is still exportable.

If anyone knows how to make the Ghost block “real” or that would be very helpful, thank you.

Ghost Block 1.3dm (212.4 KB)

Hi Peter -

That 3dm file you posted probably doesn’t reflect what is happening with the DWG file.
In that 3dm file, there is a block definition but no block instance. That is perfectly fine for a 3dm file and everything that you describe sounds normal in this situation.
To make it “real”, you simply run the Insert command and insert an instance of that definition.

Hi Wim,

“Simply” - unfortunately there’s 3000 blocks in this drawing - finding all the “missing” ones and reinserting them in the correct positions isn’t very practical.

Thank you for your time anyway.

Hi Peter -

I understand.
I’m afraid we’d need a DWG file that leads to the situation that you’re having to be able to try and find out what’s going on. In case you can privately share one of these, there’s Rhino - Upload to Support.

There’s a possibility these are Autocad proxy graphics.

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I can see if I can try and save something, I don’t have access to autocad myself, so am relying on other people to try and help export the relevant info, and really don’t think I can send 3rd party proprietary drawings.

Not sure if it is proxy entities from the description in that link - there’s no problem in autocad or the viewer - everything is there and works, just importing the dwgs to rhino, the blocks vanish from the workspace.

Hi @peterwells,
I am not sure what I am missing here, but all I am not finding that the file you provided to be out of the ordinary. Ghost Block 1.3dm simply opens in Rhino with an unused Block definition Ghost Block.

I agree with @wim. This is a block definition that has not been inserted, or all instances there were inserted have been deleted. However the block definition remains until it is purged.

If I save as DWG and open in AutoCAD, the assessment is the same. The block definition is unused.
You can use the Purge command in Rhino or AutoCAD.
This is very common practice in both applications.

You can write a script to purges all files of unused Blocks, Layers, Linetypes and more unused named
When you Purge a block in Rhino, all the named objects used by the block are purged too. In AutoCAD, you need to do a second purge to remove the newly unused named objects.

Currently Rhino and AutoCAD show this is simply an unused Block Instance.

I can try the AutoCAD Viewer tomorrow.

Please help us understand why this is more than just an unused Block instance.

Mary Ann Fugier

Hi Mary,

I don’t get why the block needs to be inserted is the problem. I wasn’t sure if I was missing something that was causing some of the blocks to not be visible, hence asking here.

I thought maybe it was the update as I have never experienced this before, then in a few days after I updated it has happened with 3 different DWGs from 3 different companies with the one exact block I need to use disappearing when opened in Rhino each time. I guess it’s just a fun trick of the universe. Other blocks in the drawing are appearing in rhino as expected.

I used the autocad viewer to comvert the files to 2010 and opened it in rhino 5 and all the blocks are in place, so I guess that’s a work around.

If I can get time to create a version of the file that I can submit I will try that.

Thank you

Hi Peter -

Since you mention that it works correctly in Rhino 5, let’s see if going back a few SRs is making a difference in Rhino 7.
The current version is SR 26 - do you tend to be on the latest?
Here’s SR 24 just to test that and we’ll go from there.

Hi Wim,

I try and keep the latest version installed, depending if I have time. I did install 26 as that popped up earlier just in case, but the issue persisted.

Using SR 24 and the blocks are visible as expected, and how it displayed when opening the 2010 converted version in Rhino 5.

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Thanks for confirming that, Peter!
It looks like a change in the library we use to read DWG files is causing this issue.
Not showing block elements is on our list as RH-72439 Open DWG: incorrect blocks in Rhino

Thank you for your help Wim. Sorry if I was not explaining very clearly what the problem was - I don’t use blocks very often.

Do you still need a dwg with the issue? I have managed to save a section of a drawing with a magical disappearing block and the 3rd party data removed if that helps.

Thanks, Peter

Hi Peter -

I’m pretty confident that we’ve identified the source of the issue, but if you have a DWG file that you can share, we can add it to the YT item so that we can make sure to test that specific file when this gets resolved.

RH-72439 is fixed in Rhino 7 Service Release 29 Release Candidate

Thank you very much for the update Brian!

That works with the dwgs I was having problems with.