Why do all (STEP file imported) nested blocks appear duplicated on top of each other when you try to edit them?
It makes it impossible to do any editing on a block instance in shaded mode!
Using the latest Nvidia Studio Driver on a 1080 and Rhino V6 SR20 (although it has been like this since I started using Rhino and I’ve seen it on multiple computers).
NOTE: This glitch goes away when you close the Block Edit.
No idea.
Can you please post a simple STEP file and the instructions to repeat the issue?
Have your drilled down on the imported file?
Is it possible the surfaces are duplicated?
Hello - yeah - this is not exactly right but currently expected as I understand - there needs to be a locked copy of the parent block in place, is what I think is happening - it would be a good thing to tune up.
https://mcneel.myjetbrains.com/youtrack/issue/RH-56136
-Pascal
It’s super easy to see in the file Pascal posted too:
Is this not the way to edit blocks in Rhino?
Can I bump this, because everyone seems to think this is normal and I’m just stumped.
Is it really a limitation in Rhino that you can only edit block instances in wireframe mode?
What is your proposed solution in shaded mode? Do you want the original block to not draw at all?
I’m not sure what you mean by “original block”, but I do not wish to have a dark grey duplicate behind what I’m currently editing causing z-fighting issues so I can’t see what I’m doing… if that explains it. 
Yes this is another annoying ( nested ) block bug. If you delete something from the block or do any other edit to it, you keep seeing the deleted item until you click ok.
I get the feeling that the code for blocks is so screwed up and scattered throughout Rhino that no developer dares to touch it.
It should work just the same as with non nested blocks, so, no duplicate geometry!
OK, I added that detail to the bug report.
I would add that this is so crippling in functionality that I really hope that the fix goes into the next V6 SR and not just the V7 WIP…
6 years for a fix… better late than never I guess!
But if anyone reads this thread and want a fix which works for V6, V7 and V8, a plug-in developer released a block editing replacement (two years earlier than McNeel) which fixes this and adds all sorts of wonderful enhancements (which McNeel still haven’t gotten around to adding):
