Designer - Seeing outline of shape when no stroke width or colour is given

[GarryP]

Windows 10, Designer 1.6.5.123 (also happens with the 1.7.0.178 Beta but that's by-the-by).

I was experimenting with shapes and noticed something strange, see attached image.
The image shows three different ways of doing the same thing (I've also attached the afdesign file).

On the left I have:
* a black rounded rectangle with a white triangle inside it at the bottom-right;
* the same as above but rotated and made smaller.

In the middle I have:
* a black rounded rectangle, a copy of the same rectangle as a mask for a white triangle at the bottom-right;
* the same as above but rotated and made smaller.

On the right I have tried to use compound layers but got the same result.

I can't seem to get rid of the very thin black line around the shapes.
Is this a bug, or am I doing something wrong, or is this just expected because of how vectors work?
Is there a way I can stop this from happening without 'cutting' the shapes up (or making the black rectangles ever-so-slightly smaller)?

lines around shapes.afdesign

[Gabe]

Hi @GarryP,

Try this:

Next, make sure your triangle exceeds the boundaries of that rectangle, as currently, they don't.  Once you resize them, the thin lines are gone. 

Thanks,

Gabe. 

[GarryP]

Thanks @GabrielM

The 'Use precise clipping' setting went a little way to fixing it by itself but I still needed to expand the triangle - as you mentioned - in the case of 'layers within layers'. Not a perfect solution but it will do for me.
Expanding the triangle didn't work with 'layers and masks' - see first attached GIF - but I may be doing something wrong.
Neither did it work with 'compound layers' - see second attached GIF that also displays some other weird flickery/inversion/reshaping behaviour - but, again, I may be doing the wrong thing.
Could you advise please?

The only thing I could find in the Help about "precise clipping" was the fairly unhelpful sentence: "Choose a clipping option for optimizing performance." Could this be expanded upon - maybe with a visual example - to give the user more information? (The Preferences page could do with having a lot more information on it in general, especially for amateur users like me, but that's a separate issue.)

I read the information given by MattP here: https://forum.affinity.serif.com/index.php?/topic/10571-precise-clipping/ but I still don't really understand what's going on. I could ask for a more technical explanation but that might just make things worse. Do you know where I should be looking to find out more about this sort of thing? It might be useful to me in the future.

[Gabe]

Re: Matt's reply: The "precise clipping is just a visual "trick". It has got a toggle because it might slow down your workflow with complex designs, as this "precise clipping" takes a bit of extra power to render it nicely. At export, precise clipping will always occur. 

You've got a lot of layers misaligned. 

See below. 

[GarryP]

Ah, I see what you mean about the misaligned layers @GabrielM

I thought I'd only used snapping and in-situ duplication but something must have gone wrong somewhere without me noticing it.
I tried again - this time just using simple rectangles, a mask, and making sure I don't move anything - and I still get the same problem, even on export.
I know I'm probably being pain but could you look at the attached GIF and file please?

In the GIF I:
* Create a new document;
* Revert to defaults;
* Create a white rectangle (as a background to show the problem);
* Create a black square (making sure it has no outline);
* Duplicate the square twice;
* Convert the middle square to a curve, delete the top-left node, and make it white-filled;
* Select the square above and Mask to Below;
The "outline issue" is evident (but I accept that it's just the way things are drawn, as you said).
I then:
* Go to the Export Persona;
* Select the Artboard slice;
* Set it to export as PDF (for export first, by mistake, then print);
* Export;
* Open in Acrobat Reader DC.
The issue is still there.

Am I doing something incredibly stupid (not the first time, even in this thread), or is there really a problem?

Update: I've just check this with the latest Beta Build 184 too and it evinces the same issue.

more outlines on squares.afdesign

[Gabe]

Right. I will log this as an improvement, but, this seems to be caused right after you delete that node. So my thinking is that, by deleting the node, that curve does not have perfect 90° and 45° angles, which might (or might not) relate to this. 

Draw a circle - shift constrain so that it is a circle and not an ellipse. Duplicate it and rotate the duplicate - the angle does not matter. Now select both and subtract. You will see some points have been created. This is the result of that circle not being 100% round. Using curves, you can never achieve a perfect circle. Visually, they look the same. But when subtracting them, you will see that there are some sub-pixel shapes. In real-life, you would never notice this. 

Right, now back to your example. You can rectify this by making the shape slightly larger, as explained above. 

[GarryP]

Ah, well as long as I'm not doing something totally silly I can live with it doing what it does.
(I tried your workflow and it does indeed produce interesting results. Doing the same for a pentagon rotated by 72 degrees shows a similar oddness.)
This is not a big problem for me as I can easily get round it, but it may affect others more so it's good to hear that it has been logged for consideration.
Cheers.