Deleting many holes at a time



Hi everybody,

Working with an imported perforated metal sheet box model I’m being a bit frustrated when it’s time to delete some of the hundreds of holes that are made into the sheets.

Using Deletehole or Untrim I can only delete holes one by one (I can also delete them all with Deletehole > All and the same with Untrim > AllSimilar, but it’s not helpful in this case since I just need to delete many of them.).

Is there a way to delete many holes through window selection or similar in order to clean a complete row or area faster?

Thanks there!


If it’s a uniform thickness sheet, I would just do a DupFaceBorder on it, delete the original, delete the holes (circles) that you don’t want, then re-extrude the part…

Another thing might to be to window sub-object select the holes (ctrl+shift+window) and delete them, that will delete the inside hole surfaces. Then Cap the object and MergeAllFaces…



Hi Mitch,

It is, so your steps would work. Maybe the DupFaceBorder is the fastest way, so we must be careful with the “Creating meshes…” moment after any operation (join, edge dragging, trimming, etc.), it may be really desperating when there are hundreds of holes.

Even though it’s a better option than what I found, I still thinking that it’s so tedious if we only have to erase (for example) a 30 hole arrow on a 12x30 holes array and the sheet is also folded on its sides, so we have to work the extrusion to match it with the neighbour sheets… Anyway, the real point may be to avoid designing metal sheet products with Rhino if possible, but sometimes shit happens…

The SubSelection+Delete+Cap+Merge was revealing too, so I was not counting on Cap and it’s a perfect tool for this context… Anyway it messed up my sample sheet on the last step… I don’t know why…

1 - Sub-Object Selection

2 - Deleting

3 - Capping

4 - Merging all coplanar faces (that happened with two different sample sheets)

Thank you!


Hmm, me neither… That looks like a display mesh error due to bad edges being created. Can you post the sample file to test here?

If possible, to avoid creating meshes every time, you could work in wireframe - make sure no shaded part is visible… Once the editing is done, go back to shaded and Rhino will recreate the meshes only once.



Here is the sample file:
DELETEHOLES0.3dm (323.4 KB)

I’ve tried Adjusting the mesh density to 1 (it was .65) and the problem has not been solved, but near… If I explode and rebuild the surface it finally works, but come on…
Thats how it looks after the mesh adjusting…

Thanks for mention the “wireframe trick”, I forgot it, but in cases like this one it uses to display a confusing view where circles from both faces look mixed. Anyway it’s a good trick and it also helps to save lighter files and faster opening. Vital if our machine is slow.

Thank you Mitch

(Pascal Golay) #6

Hi Jordi - the way to fix this is to ExtractSrf one (front or rear) face, delete it and Cap the remaining part, then repeat for the other side. But… this is pretty ugly… was the original part one with a full grid of holes, displaying normally, and then, what was the process you finally used to get fewer holes?



Yeah, that does look bad - the two outer surfaces become bad objects if you explode the part - I tried to reproduce what you got, but here it seems to work fine… Do you have the original part with all the holes before deleting some?



First, I draw a rectangle and a cicle array.
Next, I extrude it all and made a boolean difference.
The rest is already known…

I’m posting the model just before the boolean:
DELETEHOLES01.3dm (523.8 KB)

Thank you


Dunno, seems to work here with your model… --Mitch

(Pascal Golay) #10

Hi Mitch, Jordi - It is messy here - Sub-select one hole, delete, Cap, MergeAllFaces … ugh.



Thank you Mitch,

What do you think it can be the difference? I found the same problem working with the real metal sheet box…


This is a characteristic problem when doing this kind of models and operations… at least with my workstation… but why??

(Pascal Golay) #13

Hi Jordi - in this case, I blame MergeAllFaces for now at least - I’ll test V6…

Same in V6. On the pile it goes.



Why does it work perfectly here (one hole or several, window or mouse pick)…??? --Mitch

(Pascal Golay) #15

Good question… Pondering…
Mitch, you’re just opening Jordi’s file, right, not importing or something like that? Do the BD, get the history warning and then sub-object select , Delete, Cap MergeAllFaces… ? Messes up here, so far, with any hole deleted.



OK, I did get it to fail now. Originally I opened the file directly from Jordi’s link, did the BD and then started deleting. It worked fine. Now I saved the file to my desktop, closed Rhino, reopened the file, and now I see it fail.

This is really weird, I figured out what made the difference… When I opened the file the first time, I had RhinoCAM loaded. It does not fail with RhinoCAM running! After I disabled RhinoCAM, I get to fail. If I re-enable RhinoCAM, it stops failing…

Go figure that one… :confounded:

(Pascal Golay) #17

Hi Mitch - Yikes. Can you please save a with and a without RhinoCAM version and post or send to me? Thanks for the sleuthing…




No problem - I will send you a small set of files shortly… --M

Edit: file sent to your e-mail…


Hi again Mitch and Pascal,

Sorry but I’ve had a hurry at the office…

Please @Helvetosaur, send me or post here the set of files too, so I can try the difference with and without RhinoCam. It’s not installed into this computer but I can try with others…

What is RhinoCam doing with the mesh? maybe analysing it more deeply in order to prevent the machining?

Looking forward to understand this at all…

(Pascal Golay) #20

Hi Jordi - it is not the mesh, the front and back faces go bad (and makes an ugly mesh) if RC is not present and do not if it is present - at this point it’s all a complete mystery… I was not able to see anything in Mitch’s files that explains anything (to me, but I’ll see if I can’t get a developer to have a look.)