This is what's wrong with the brush in affinity photo

[ZufDraw]

I've had a hard time adjusting the brush to act in a natural way for drawing. I've compared with mainly photoshop and sketchbook pro and posted numerous reports about this. There are a few issues like jagged lines on low zoom levels and general inconsistent behaviour of hardness and size. Things you only notice when drawing or writing by hand on a tablet or Cintiq.

Now I think I found what causes the latter! I was able to isolate what is going on by setting the shape to a narrow ellipse and the stroke to large spacing. Look what the preview shows. There are 2 things going on here:

1 Inconsistent size toward the beginning/ending of the stroke, causing a sort of 'arrow head' effect

2 The increase of the amount of dots towards the ending is too steep. Meaning the spacing between the dots in the end is near zero and in the middle pretty large. Some decay in spacing is useful since the relative spacing between dots should stay the same. But it seems that AP does not take the dot size into account and at certain settings the decay is much to steep, causing too many dots to overlap. I noticed that in photoshop and sketchbook pro this decay is far less and generally in better balance with the shape size. This presumably results in their smoother line behaviour. One result of this steep decay in AP is that soft lines are much harder in the endings than in the middle and pressure sensitivity feels a bit 'off'.

All in all this explains the strange behaviour I was experiencing. This arrowhead effect is nearly invisible in the preview when the shapes are rounder, but in practice I always notice the inconsistent line behaviour because of this. 

Affinity photo:

A drawn line to show it's not just the preview:

 

photoshop:

sketchbook

 

lastly look at this soft line and how hard it gets near the endings. The steep decrease of dot spacing is what causes this. 

 

In all examples these are the dynamics settings:

In my opinion two things need to change:

1 The arrow head behaviour is just off and needs to be fixed.

2 The spacing between the dots needs to be rebalanced in order to have a consistent line behaviour throughout different settings of spacing, dynamics, hardness etc. Generally speaking the dot SPACING needs to be in balance with the dot SIZE and SHAPE. E.g. the thinner part of a pressure sensitive line should be equally soft as the broader part of the line. Also when pressure sensitivity is set to linear, the line thickness change should also be linear. This is currently not the case and my guess is the inconsistent dot spacing causes this. 

I hope this helps refine the brush behaviour for AP!

 

[MadPropz101]

Amazing investigative work here, I'm glad that somebody is actually invested in this issue. The jagged lines are the main reason why I am unable to make the switch from Photoshop.

[loukash]

This thread should be moved to forum.affinity.serif.com/index.php?/forum/77-photo-bugs-found-on-macos

@Chris B?

[Frozen Death Knight]

This could also possibly explain a bit why there is such a huge delay when doing fast brush strokes with Hardware Acceleration on Windows. The amount of dots created at the beginning and end of each stroke is likely making the computing skyrocket. Of some reason this slowdown doesn't happen to the same extent with regular CPU computing, but the inconsistent brush stroke spacing likely doesn't help.

Good detective work, by the way!

[ZufDraw]

On 4/7/2021 at 1:15 AM, loukash said:

This thread should be moved to forum.affinity.serif.com/index.php?/forum/77-photo-bugs-found-on-macos

@Chris B?

I initially posted this in the general forum since it’s not platform related. It occurs on OS X, win and iOS afaik

[Gabe]

Hi all,

Sorry for the delayed reply. Issue now logged. 

[ZufDraw]

Thanks!

Another pointer for where to look are these two settings. With the shape zet to (near) zero you can see the different behaviour from tip to body.

 

Good luck!

[ZufDraw]

BTW in my latest example the pressure is set to 99% (linear). This might be relevant because when I set it to e.g. 96 the effect is much less prominent and is back at e.g. 93% etc. The issues are seemingly random different at certain pressure settings. 

[ZufDraw]

any progress on this issue?

[Julia04]

@zyfdraw they only register a problem with brushes (I'm waiting for an answer too. Most brushes don't work correctly

[Gabe]

I'm afraid I don't have any updates. Sorry. 

[Julia04]

@Gabe thank you for the honest answer. It at least allows us to understand the current state of affairs.

[ZufDraw]

Is there anything more you could tell. Can we expect this to be fixed -eventually- since it is 'logged'. Is this some kind or priority or is it on a long list of "whenever there's time left". Is this hard to do and therefore will take some time or is it an easy fix. Anything. For me it's critical so would appreciate a little more indication of what to expect. 

[Julia04]

@ZufDraw great question for developers! but I don't think they will answer us (
I waited so long for an answer that I found an alternative to affinity and now I just go to the forum to make sure once again that the developers do not care about this problem. 

[Gabe]

We can't provide ETA for bug fixes, so there's not much info I can provide at this point. 

[ZufDraw]

A friendly bump for this issue. I know it's been only 2,5 months but something tells me this could be quite simple to fix.

Also, the jagged line thread was closed(?), I wasn't able to reply to that thread anymore, but that's an equally annoying issue especially for us hand drawing artists.

In short: when zoomed out more than 50% quick strokes become jagged. 

 

 

[Snuggs]

I know this is an old thread, but I just wanted to check if this has been resolved? 

[Gabe]

I'm afraid no. Sorry.