Polygonal Lasso snapping to pixels when snapping is off

[imfastrnu2]

I cannot figure out how to COMPLETELY turn snapping of for the Polygonal Lasso tool. It's difficult to describe so I've included images. Basically, if I turn all snapping off in Photoshop I can Lasso select between pixels which is truly free selecting. When I try this in Affinity Photo it  snaps by pixel, there is no "between the pixels". Please refer to the images to see what I'm trying to say.

I need Affinity to stop snapping to pixels and let me select the way Photoshop does.

[firstdefence]

I assume this is Adobe Photoshop compared to Affinity Photo?

How does the actual selection look in comparison, I suspect Adobe will have to make a choice between the left side or right side of the polygon line. I'll check in Adobe.

An alternative way is to use the pen tool to make the shape you want and then convert it to a selection, this requires that the shape has a fill first.

[firstdefence]

As I thought, Adobe picks the closest pixel edge.

There is an element of ambiguity in how adobes non-snapping selection works, so you have to be aware of where the selection is made, doing the same thing in Affinity Photo removes that ambiguity and lets you make the selection you want because it's only going to be the pixel edge to the left or the pixel edge to the right.

[imfastrnu2]

Ahh...I see exactly what your saying now. I think what's happening is the "feel" of selecting for me. In Adobe I can move about freely between pixels why selecting but when I catually close the selection loop it does indeed jump to the nearest pixel edge. I simply wasn't noticing that because I'm generally not zoomed in that far when I close the selection. Affinity's lasso just jumps to the nearest pixel edge no matter what. I'm fine with that, now that I know exactly what's happening.

 

Thank you!

[stldoug]

I know this is an old post, but this feature has bugged me for a long time.

On 8/9/2019 at 7:54 AM, firstdefence said:

As I thought, Adobe picks the closest pixel edge.

This is not entirely true. It may appear that it's snapping to the closes pixel edge, but the actual selection is a percentage of that pixel. I don't have photoshop anymore, but Photopea has the same functionality. Compare the two selections here. As you can see, when deleting the selection, it's not deleting just the pixel, it's partially deleting the neighboring pixel as well.

Affinity Photo 

Photopea (Online Photoshop clone)

[sfriedberg]

So basically, if you make a selection "off the grid", you want automatic feathering of the affected area based on the proportion of the selection that falls within a given boundary pixel?

If so, you can probably approximate this yourself using masks while waiting for Serif to act on a feature request.  And you should make that feature request.

Are you doing pixel art or other super-blocky style?  If not, I wonder if a simple smoothing operation at the boundary would serve as well as this more precise auto-feathering.  If you do expect people to see the individual pixels, smoothing would look somewhat different, I am sure.

[stldoug]

I use it for manually masking objects. A good recent example is the follow photo. A client asked me to make changes to the back wall, so I have to mask out all the items. The magic wand and selection brush tool are helpful, but things like the flowers and even the lamps are easier to just manually select with the lasso. You can see in the lamp below, that I used the selection brush to mask out the lamp, but trying to use the lasso to "smooth" out the rough edges sucks, because it's forcing me too the pixel grid.

I would be okay with them making this a toggle. i.e. Toggle auto-feathering, or something like that. 

[sfriedberg]

When using the lasso to tweak your selection, turn on Antialias and/or set Feather to something like 1 px, 2 px or 3 px, instead of zero.  Or, turn on Quick Mask and use the paint tools, setting a low Hardness on the tools.

[stldoug]

On 3/20/2025 at 4:58 PM, sfriedberg said:

turn on Antialias and/or set Feather to something like 1 px, 2 px or 3 px, instead of zero.  Or, turn on Quick Mask and use the paint tools, setting a low Hardness on the tools.

Yep, I've done all that... Anti-aliasing was on in this scenario. Feathering would have been too much "blur", since this photo didn't have a lot of detail. Quick mask doesn't really help in the situation, because of the light/shadows behind the vase, there's not enough contrast to define the edge. So I wind up taking more time to "clean up" the bad selections. Just like what you are seeing with the jagged edge of the lamp.

My personal opinion, it's way easier just to manually select it with sub-pixel selection.

Thanks