Moving frames in Affinity Designer results in bug when exporting

[peternoot]

Hi! I've been working with Affinity for over a year now. While it is an awesome product, I got frustrated quite often when exporting a document in Affinity Designer with multiple frames and checking the result, only to find there was an extra pixel in the width or height of the result. For example I had a social media illustration on 1080x1080 and it resulted in an image of 1081x1080. That extra column of pixels would also be white, or just very inconsistent with the rest of the image.

I finally understand what happens here and how to work around it. However it would be better if the workaround wasn't necessary.

To reproduce:

Start with a regular frame. In this example I make one of 10x10 pixels (72 dpi). I add a red rectangle at the bottom half of 10x5 pixels to make the issue more clear. I clone the frame and I  move the second frame to the right. I ended up with the second image positioned at 13.6 px on the X axis. Now I'm going to the export persona where I find my export being 11x10 px. 

Now I export the resulting frame, which results in a 11x10 image, I open the result with Affinity and voila:

 

Workaround:

To solve this I have to use the transform view and enter a X/Y position for the frame which does not include decimals. This feels really unnecessary and unintuitive to do though.

Edited January 11, 2024 by peternoot

[GarryP]

Welcome to the forums @peternoot

What you described as a “workaround” is simply what you need to do because the Affinity applications work this way.
It’s not a bug, it’s just how the software has been designed to work.

If you want pixel-perfect export then you need to make sure that the layers in the export (and their contents/formatting in some cases) are pixel-aligned (integer pixel values).
Otherwise the software will create extra pixels to accommodate the ‘missing information’ for the ‘sub-pixels’ upon export.

To try to make sure that layers are pixel-aligned you can set “Force Pixel Alignment” ON and “Move By Whole Pixels” OFF in the Toolbar, but this is not retroactive so any existing non-aligned layers may need to be moved.

There are some people who don’t like it, and have said so many times in these forums, but it’s what we’ve got.

[loukash]

21 minutes ago, peternoot said:

I  move the second frame [artboard] to the right […]

… to the 13.6 px position which means the whole artboard is off the document pixel grid which means all content of the artboard will be subject to antialiasing.

Solution:

Make sure all your artboards are aligned to integer pixel values.

[Old Bruce]

When doing Pixel Perfect work have Snapping on and have only Force Pixel Alignment turned on.

You may have a Pixel Grid set up and in that case you can have Snap to Grid turned on as well.

[peternoot]

Thanks for the replies and tips. I understand what's happening and why it behaves as it does, I just really have the feeling this should not be expected behaviour.

[thomaso]

5 minutes ago, peternoot said:

I just really have the feeling this should not be expected behaviour.

Note that your thread got tagged in the meantime together with other threads (2019) by Serif as an issue for further investigation by the developers:

https://forum.affinity.serif.com/index.php?/search/&tags=afd-2424

[loukash]

1 hour ago, peternoot said:

I just really have the feeling this should not be expected behaviour.

The highly confusing issue here is that the user isn't made aware that Affinity documents have an "absolute pixel grid" that rules it all.
In Designer, each artboard will confusingly display its own ruler and pixel grid, even if it doesn't match integer pixel values of the document's absolute pixel grid.
That's the proverbial "root of evil" that will inevitably result in antialiased objects on export.

Publisher pages are affected just as well, for that matter.
Also, having bleed active adds to the issue as well.

So in Designer, make sure that you always have the Pixels View Mode active when working at single pixel zoom level.

On the other hand though, there are valid scenarios where you don't want to align objects to the pixel grid. But this advanced flexibility comes with a price…