# Rounding corner of a single point in a structure

Hi,
I need help in rounding individual corners of a shape. The main aim here is to make some of the edges blunt in my design. When I try ' Round corners' option, whole structure is changing. How to change specific corners without altering all points. Thank you in advance for the help!

• Hello,

Maybe can refer to this first, this method round the stuff that you select only
https://www.klayout.de/forum/discussion/comment/9139#Comment_9139

By the way, if inner / outer radius feature is not enough, maybe you can try this one,
which provided by Matthias, it can select edges by angle, and works under DRC macro

``````original = input(...)
patches = original.notch(1.um, angle_limit(91.0))
(original + patches.polygons).output(...)
``````

https://www.klayout.de/forum/discussion/2115/chamfer-function-for-fun#latest

Vincent

• How about making a "cutter" object (say, by subtracting
a circle of desired radius, from a square) and then using
that "cutter" on the target object? Both using the "Subtract,
Others from First" operation? All straight layout moves, no
macro development.

If you have varying orientations besides Manhattan you
might need to make multiple "cutters" to match.

Of course a "Round Corners" that worked with Partial
Selection would be nice. But the Partial tool is a bit
"clunky" and "Round Corners" needs the object to be
a polygon w/ N>=32 vertices (won't touch a Box)
anyhow.

I've verified that making the "cutter" is easy and using
it, "surgical".

• edited February 2023

I'm sorry, there is no "round only one corner" feature.

One way to do single rounded corners is to create a rough polygon and add rounded corners by placing a circle. In this case I created the circle by taking a 12x12 square and using "round corners" with a radius of 6 on that. My "rough" polygon has a chamfered corner:

You can leave it that way or merge both shapes to get a single polygon. Merging however is irreversible.

Matthias