I just want to chamfer one corner

I’m just learning. I have a cube, all i want to do is chamfer or find a way to cut just one corner off, i cant find anything online apart from lots of code and I cant understand why it would be so difficult a task

There isn’t a specific tool for that but it’s not hard to do.

  1. Place a sphere with a radius you want with it’s center at the corner
  2. Use Intersect to make curves where the sphere intersects the cube
  3. Delete the sphere
  4. Draw a Polyline that connects the three points where the arcs meet the cube edges
  5. Use the Polyline to Trim the cube
  6. Use the Cap command to create and Join the triangular surface
  7. Delete the three arcs

I found that placing points on intersection with osnaps didn’t really work. At least the intersections were found only for the one isocurve, requiring to rotate the sphere all the time.

Instead of directly placing points I selected both the cube and sphere, then used _Intersect. The sphere could be thrown out, and then a Polyline with osnap on ends worked fine. Otherwise further as prescribed.

I use reg _Chamfer on the corner edges & trim & cap

(vertex chamfer would be a great feature to have ! for multiple vertex operations)

Good catch @nathanletwory
I edited my steps to reflect that.

Many thanks i was drifting toward an answer of sorts but couldnt quite get it to knit together

Hi @andy1johnstone, All - I had a crack at making a tool for this - try it out if you’re feeling adventurous, it might work OK-

To use the Python script use RunPythonScript , or a macro:

_-RunPythonScript "Full path to py file inside double-quotes"

Note equal setback distances when more than three edges are involved do not, in general, allow a planar cap, so there’s necessarily some fuzz there - I took it as more important to make a simple planar surface than to guarantee the distances.

Another thing to note is that this uses a cheap Boolean operation, so if your object is not closed you may get the wrong answer - use Flip to sort it out.


this works great! please buzz if u decide to update to handle multiple corners ; ]

Hi Yelen - for now try this on a macro

*_-RunPythonScript "Full path to py file inside double-quotes"

With the * directly (no space) in front of the _-RunPythonScript. * is a repeater…
(I have not tried it here)

Hi all,

I find this thread kind of crazy and terrifying. As much as I admire McNeel’s dedication and support to us, the customers, I also feel that some basic modeling functionality should be there, coded, default and working. Corner fillet/chamfer should be part of that basic functionality. Just me thinking that?

Sending a newbie to follow long workarounds that might fail, or load scripts reminds me of this:


Well, not a newbie as such, certainly not to coding but my belief is that if you need to run your own script to do something then it probably isnt needed, but chamfer a single corner of a Cuboid id expect that to be at least a basic function or even an angular cheesewire

Hello - you could run the script or wait till V7, at the earliest… up to you.


I don’t recall anyone ever asking for this before.

I think every software has its own great set of tools & beyond that, this forum
platform is fantastic for requesting/suggesting features & get help.
I remember asking for many Rhino features back in modo forums ; )
@pascal thnx for that nice lil’ trick to repeat! works perfectly!

Yeah, I was messing with shapes like that in testing - it makes an interesting and nice progression - I wonder if that shape converges on some predictable shape like a parabola or something.


you might have inadvertently introduced a whole new tool set for v7 ;]

Yelen I think you figured out Pascal’s script-activist ways to get things into new builds :rofl:

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Hi Pascal

Im getting this running your script, tried it with the cuboid joined and exploded with no luck:

Message: ‘Extrusion’ object has no attribute ‘Location’

line 51, in ChamferCorner, “C:\Users\Andy\AppData\Roaming\McNeel\Rhinoceros\6.0\scripts\chamfercorner.py”
line 94, in , “C:\Users\Andy\AppData\Roaming\McNeel\Rhinoceros\6.0\scripts\chamfercorner.py”

theres more to the story though, im trying the script on my newer HP laptop running an intel iris 6100 graphics card and osnap just will not work on it, i have an older HP that works (laggy but fine), looking through the script it seems as though this shouldnt matter and its looking for a location in space of the centre of a sphere as per the method given above however im new. No osnap is a truly pain

Yeah - use ConvertExtrusion first - I have not got it handlng extrusion objects yet,


Pascal, Ideal works a dream and rolling back my graphics driver has fixed my osnap problem so many thanks