Erratic Ellipse shape with outer stroke and small radius

[NotMyFault]

Hi,

1. new document, sRGB, small size
2. activate dual view pixel / vector
3. add ellipse shape (circle), radius 4px, no fill, black stroke, align outside
4. reduce radius below 4px
5. play with join type

expected: get a nice circle of given radius px 

observed: rendering gets erratic. The circle is probably based on 4 nodes, which can’t handle tight radius

2nd bug:

transform panel allows negative input which gets interpreted as positive numbers

[Paul Mudditt]

Struggling to replicate this, you say radius of 4 pixels but you actually have stroke/line width set to 4 pixels? Is it sensible to have a circle size less than the line width?

Anyway seems same as V1 and with line width larger than circle radius seems to be a minor maths/drawing artefact only to me perhaps?.

[NotMyFault]

7 hours ago, Paul Mudditt said:

you say radius of 4 pixels but you actually have stroke/line width set to 4 pixels?

Yes, start with both set to 4px.

Then, reduce radius (not stroke width) of circle to trigger issue.

7 hours ago, Paul Mudditt said:

Is it sensible to have a circle size less than the line radius?

Why not? Affinity should document such restrictions, or filter input in cases it is not valid.

i know of course you could make a larger donut shape and use fill instead of stroke. But you may want to use a special brush for stroke, which cannot be replaced by using fill. Vector curves (closed one) allow any stroke size, totally unrelated to the size (bounding box) of the shape.

[Paul Mudditt]

3 hours ago, NotMyFault said:

Yes, start with both set to 4px.

Then, reduce radius (not stroke width) of circle to trigger issue.

Why not? Affinity should document such restrictions, or filter input in cases it is not valid.

i know of course you could make a larger donut shape and use fill instead of stroke. But you may want to use a special brush for stroke, which cannot be replaced by using fill. Vector curves (closed one) allow any stroke size, totally unrelated to the size (bounding box) of the shape.

But stroke/line width greater than the radius means the stroke is wrapping back on itself like turning inside out. I can see why it would be hard to trap that case in software, at least it does not crash and handles it as best it probably can I think.

[NotMyFault]

1 hour ago, Paul Mudditt said:

But stroke/line width greater than the radius means the stroke is wrapping back on itself like turning inside out

Not if you use „outside“ alignment as i have stated in step 3 of my starting post.

 

13 hours ago, NotMyFault said:

add ellipse shape (circle), radius 4px, no fill, black stroke, align outside

 

[Lee D]

Thanks - logged and passed over to the developers.

[Lee D]

@NotMyFault I've been retesting this issue and can't get the same results as you show. Can you please do a screen recording starting from creating the document and provide a sample test file as well. As I can then also update the report.

[NotMyFault]

It seems issue is no longer reproducible on V2.2

Even the circle in vector view mode looks differently now.

can be closed.