Corner tool bug

[Brian M]

I'm seeing an odd bug with the corner tool where some nodes are ignored by it, even when all are selected by it. I have reduced it to a simple example and attached the file.  Notice how there are five sharp corners.  There are no extra nodes in the shape.  I tried closing and reopening as suggested in https://forum.affinity.serif.com/index.php?/topic/123720-weird-thinks-happens-while-using-corner-tool/, but that didn't help.  If I export to SVG, then open the SVG in Designer, it works fine. 

 

corner-bug.afdesign

[prophet]

I think you've got some tiny, but non-zero length rays/handles on those nodes that are causing issues. I can select the nodes, convert to sharp and reapply the rounding and it seems to work.

[Brian M]

You're right, thank you! No idea how they got there – some of them are invisible even at max zoom level – but that fixes the problem.

[prophet]

Happy to help.

[Brian M]

Turns out they are zero-length.  This is the path data.  

<path 
d="M46.694,15.778C46.694,15.778 46.694,0 46.694,0C46.694,0 31.129,0 31.129,0L31.129,15.565L15.778,15.565L15.778,0L0,0L0,15.778L15.565,15.778C15.565,15.778 15.565,31.129 15.565,31.129C15.565,31.129 0,31.129 0,31.129L0,46.907L15.565,46.907C15.565,46.907 15.565,62.472 15.565,62.472L31.343,62.472L31.343,46.694L15.778,46.694L15.778,31.343L31.343,31.343L31.343,15.778L46.694,15.778Z"/>

Probably the result of a zero-width offset operation or something.  When the exported svg is re-imported, the unnecessary control points get removed.

[Sean P]

Hi Brian M 

Glad prophet has been able to help you. Unfortunately without knowing how these handles were created there isn't anything we can investigate.

[Hangman]

@BrianM I'm not sure how you went about creating your graphic but I think it's just a case of ensuring accuracy... looking at the graphic you attached it looks to me as though you've created it using a series of shapes but that your shapes are not aligned accurately before applying any Boolean Operations...

 

I would draw my source shapes ensuring they are aligned and snapped to a grid and then do something like this...

Corner Shape Creation.afdesign

[Brian M]

 

On 7/1/2021 at 5:46 AM, Hangman said:

@BrianM I'm not sure how you went about creating your graphic but I think it's just a case of ensuring accuracy... looking at the graphic you attached it looks to me as though you've created it using a series of shapes but that your shapes are not aligned accurately before applying any Boolean Operations...

The example was reduced for simplicity, but the original curve is a twin dragon curve, and was generated programmatically and is accurate. It was done a while ago so I can't remember all the details, but what you are seeing is the result of processing done on the curve afterward in Affinity.  I likely did a stroke and offset it to create a curve with some width that I could work with and turn into a solid. Whatever it is, the zero-length handles are the result of some operation within Affinity. I'll keep my eyes open for it to happen again, and hopefully can figure out which one.