Jagged Lines (with Pixel Brush) in Affinity Photo iPad (v2.4)

[Lewisflakes]

I had this problem since I first bought Affinity Photo iPad (V1, then V2). I had hoped this problem was solved when I read that V2 had an improved brush engine, but alas the problem persits. When I draw circles with a basic pixel brush (or any pixel brush really), I get these straight lines (see screenshot below). No matter how I alter the app's settings or brush settings, the problem remains. It makes it total unusable for me to draw in Affinity Photo.

Anyone knows how I can solve this problem?

 

Related info:

- I use an Ipad Pro 12.9 (2020)

- I use the official Apple Pencil 2

- Updated to latest Affinity Photo V2.4 (problem arose in any version though)

- This problem only occurs within Affinity. No problems with Procreate, Clip Studio, etc

- Problem is unrelated to zoom levels or brush width, I get it at any zoom level and with any brush width

[stokerg]

Hi @Lewisflakes,

I can't replicate this.

Could you attach a screen recording and I may be able to spot from the recording why this is happening?  To record your screen on iPad see here

[SrPx]

Super wild idea, but one never knows... What happens if you change the brush spacing settings? Like, if it's at a 6%, trying increasingly bigger percentages (not needing to reach the point of seeing the "pattern"). I have it on 5% and goes well with everything, but on desktop... ipad version might be different. It used to happen in much older desktop versions, so, who knows. Like when there's too many dynamics on, or spacing % is too small (when doing enough of that, still happens on desktop, if one goes crazy), it did have issues to "catch up". It is all good on desktop, now, though. All this as I am supposing it is a "not catching up" problem, but who knows if in the ipad it's trying to magnetically close the circle or something (I don't think so, that's even a wilder idea).

[Lewisflakes]

On 4/29/2024 at 12:23 PM, stokerg said:

Hi @Lewisflakes,

I can't replicate this.

Could you attach a screen recording and I may be able to spot from the recording why this is happening?  To record your screen on iPad see here

Here you go. I've also added a screen recording of doing the same thing in Affinity Designer (Pixel), as the same problem occurs there. Brush used is a round brush in the Basic Brush list.

[Lewisflakes]

On 4/30/2024 at 12:22 AM, SrPx said:

Super wild idea, but one never knows... What happens if you change the brush spacing settings? Like, if it's at a 6%, trying increasingly bigger percentages (not needing to reach the point of seeing the "pattern"). I have it on 5% and goes well with everything, but on desktop... ipad version might be different. It used to happen in much older desktop versions, so, who knows. Like when there's too many dynamics on, or spacing % is too small (when doing enough of that, still happens on desktop, if one goes crazy), it did have issues to "catch up". It is all good on desktop, now, though. All this as I am supposing it is a "not catching up" problem, but who knows if in the ipad it's trying to magnetically close the circle or something (I don't think so, that's even a wilder idea).

Thanks for the suggestion! Unfortunately adjusting the brush spacing did not make any difference.

[SrPx]

Does it happen when it is not a circle?  I mean, if you make a similarly fast stroke, but not closed, that the finish point does not get close to the starting point? For example, a wave or a fast "S". 

[Lewisflakes]

42 minutes ago, SrPx said:

Does it happen when it is not a circle?  I mean, if you make a similarly fast stroke, but not closed, that the finish point does not get close to the starting point? For example, a wave or a fast "S". 

Yes, it seems to be only at the beginning of a new stroke, especially when changing the direction quickly after having started putting down the stroke.

[SrPx]

I have never used the iPad version... You have all Affinity's magnetic snapping features off, right ? (and the assistant off)

I am also extremely unfamiliar with iPads, the iPad Pro and the Pencil technology. But.. is there a chance that (like in my Samsung S7 FE) there's some extra configuration that can come by default (or which one can set up) regarding the pen?Like the S-Pen special features and "behaviors".  I am thinking of some sort of behavior you can check ON or OFF in general iOS settings relating to the Pencil. Like some "auto-connect" (when the end of the line is close to the start, as if to close a shape)  magnetic feature or a special mode the Pencil can be in. In Windows, the similar thing to that is Windows INK, and in Samsung's S and its S-Pen, there's a ton of things that are best left disabled. 

Or.. that the code in the iPad version of Affinity is somehow interacting with one of those features. But... it is the first time I hear of this with Affinity (might be just me), so, it could very well be a particular configuration. Can you check on that? 

 

Edit: Oh, wait... I will leave all the above written (as it could also affect). But Now I read it better... it is when you "start" (not when you are finishing the shape) that the straight line happens... As it is having a hard time for detecting the initial thing or trying to guess in what mode it is starting or something... This can also be affected by some extra feature on iOS, I suppose. I would play with the Pencil's iOS settings, as I mentioned, disabling and enabling those iOS settings, on and off, one by one, to see if one of those is the culprit or that interacts badly with Affinity's apps. Even could be some feature related with palm rejection/detection. I'd try everything even if remotely related.

[Lewisflakes]

11 hours ago, SrPx said:

I have never used the iPad version... You have all Affinity's magnetic snapping features off, right ? (and the assistant off)

I am also extremely unfamiliar with iPads, the iPad Pro and the Pencil technology. But.. is there a chance that (like in my Samsung S7 FE) there's some extra configuration that can come by default (or which one can set up) regarding the pen?Like the S-Pen special features and "behaviors".  I am thinking of some sort of behavior you can check ON or OFF in general iOS settings relating to the Pencil. Like some "auto-connect" (when the end of the line is close to the start, as if to close a shape)  magnetic feature or a special mode the Pencil can be in. In Windows, the similar thing to that is Windows INK, and in Samsung's S and its S-Pen, there's a ton of things that are best left disabled. 

Or.. that the code in the iPad version of Affinity is somehow interacting with one of those features. But... it is the first time I hear of this with Affinity (might be just me), so, it could very well be a particular configuration. Can you check on that? 

 

Edit: Oh, wait... I will leave all the above written (as it could also affect). But Now I read it better... it is when you "start" (not when you are finishing the shape) that the straight line happens... As it is having a hard time for detecting the initial thing or trying to guess in what mode it is starting or something... This can also be affected by some extra feature on iOS, I suppose. I would play with the Pencil's iOS settings, as I mentioned, disabling and enabling those iOS settings, on and off, one by one, to see if one of those is the culprit or that interacts badly with Affinity's apps. Even could be some feature related with palm rejection/detection. I'd try everything even if remotely related.

I can see no such settings for Apple Pencil in iPad's settings.

After having removed the Affinity Photo app and reinstalled it, resetting the settings, I did found something out. It seems to be related to the document's DPI. I tried a 1080x1920px document at various DPI:

- At 75DPI it works as intended, it gives an enjoyable drawing experience

- At 144DPI some small straight lines start to appear when drawing

- At 300DPI (at which I work the most) it seems to be the worst

- At 600DPI I get some noticeable straight lines but not as bas as at 300DPI

- At 1200DPI I got a better drawing experience than previous DPI's, though not as great as at 75DPI

I can't work at 75DPI though as that is too low and 1200DPI gives too large file sizes.

 

Update: I also tried a very large document at 75DPI and then I got the same experience as at 300DPI described above.

 

Edited May 2 by Lewisflakes
Update

[pruus]

Are perhaps you working in the new beta? In the new beta, in that version you can choose, autoclose.

[Lewisflakes]

2 hours ago, pruus said:

Are perhaps you working in the new beta? In the new beta, in that version you can choose, autoclose.

In the settings of the app I can read it's version 2.4.2.2371. Not sure if this is a beta version? I had this problem occuring in any version though.

Where can I find this autoclose section?

[SrPx]

I have no idea about beta features. But in many apps autoclose produces this effect (but you don't seem to be using a beta version?). In other software, it is just that the starting pen recognition is having issues, so, a initial delay is provoking a initial straight line due to not "catching up" due to that initial extra processing or hardware/OS issue (or the app's fault). Or in others, it's just that there's some brush lag.

An iPad Pro has I think like 16 GB in the best case scenario (and I guess, a lot of that is used by the OS an etc) or 8, depending on the version, and shared memory for CPU and "GPU"... I mean, it has not much memory (not sure if enough free disk is also an issue, like in desktops). So, big canvases could affect the brush performance, at the start of the stroke or all the time. One thing, though. If one works with a 1080x1920px canvas, if one is willing to keep the same size, and I mean, the document physical size (IE, for print) would have to be reduced (in centimeters or inches, etc) when going from 75dpi to 300dpi, to keep it as a 1080x1920px canvas. Unless we add pixels (and so, make it heavier to process) , if what we are really doing is resizing it so that, for example, an A4 document (around 29.7 cms tall) to still be 29.7 cms tall, but now at 300 dpi, instead of 75 we are then needing the document to have a lot more pixels, we are increasing it in pixels dimensions.

[SrPx]

Which are the native DPIs of retina (I really mean ppi, as the other thing does not make sense (dots is for printing), but you know), of the iPad Pro? Maybe it needs to be at those same DPI to not get extra processing to "translate" to such dpi, to not get the hiccup with the pen? As it's what only makes sense to me if suddenly at 1200 dpi it goes smoother than at 300 dpi. The dpi are only a kind of a "hack" to speak about printing resolution (it's easy to get things confused when talking about it, happens to me).

PD: What I am reading the following about the iPad pro diplay: "2732-by-2048-pixel resolution at 264 pixels per inch (ppi)"  (<--12.9 iPad Pro specs. The 11" one are a bit different)

What happens if you paint on a document that you create NEW with both those exact pixels and exact same ppi ? Does it still make the bad thing ?

[Lewisflakes]

1 hour ago, SrPx said:

Which are the native DPIs of retina (I really mean ppi, as the other thing does not make sense (dots is for printing), but you know), of the iPad Pro? Maybe it needs to be at those same DPI to not get extra processing to "translate" to such dpi, to not get the hiccup with the pen? As it's what only makes sense to me if suddenly at 1200 dpi it goes smoother than at 300 dpi. The dpi are only a kind of a "hack" to speak about printing resolution (it's easy to get things confused when talking about it, happens to me).

PD: What I am reading the following about the iPad pro diplay: "2732-by-2048-pixel resolution at 264 pixels per inch (ppi)"  (<--12.9 iPad Pro specs. The 11" one are a bit different)

What happens if you paint on a document that you create NEW with both those exact pixels and exact same ppi ? Does it still make the bad thing ?

I don't think the iPad Pro 12.9 is so underpowered that it can't handle a small basic brush in a 1920-1080px @300DPI document. That doesn't feel right. Especially if it does better at a higher DPI such as 1200DPI. Remaining storage is definitely not a problem as I have a 1TB iPad with about 700GB remaining.

I've tried 2723x2048px @264DPI. It's not as bad as 1920x1080px @300DPI, but there is definitely some small straight lines occuring (indicated with thin red lines).

[SrPx]

Yep... I'm familiar with those, the straight lines (where there should be a continued curve) happened before, in previous versions (not anymore) of Affinity desktop. It was indeed common at some point of elder versions. I have not seen that since a relatively old update of 1.x, though (on desktop).

[ There might be a bug... I just like to discard everything else, first. As if it is anything else, it would have a fast solution. ]

But that's why I also recommended setting higher spacing value. You said it did not improve... Did you try with a very wild value, like 25% (instead of the usual 5% or 6%).  Kind of to see if it's a problem of performance, or is it something else.  I'm just trying to eliminate factors or hunt down why is it not able to catch up. It might even be that you are drawing the circles at an insane speed, but I doubt that... (I have noticed some old Huion and XP-Pen pen tablets/displays had issues in making fast circles, not the case with Wacom (I have Huion and Wacom devices).

"I've tried 2723x2048px @264DPI. It's not as bad as 1920x1080px @300DPI"  I don't know what would be your take with a result like this, but this is what I find most shocking. It's more pixels, more information to catch up... And yet it's working better in the one with more pixels. Still, the way we are talking about it does not make much sense (the DPI without referring to a physical size, in measures, of the document).

The DPI (probably should say ppi) is only a way of dealing with print outputs. But really all we should care is about total pixel dimensions. As later on in Photo, or on desktop in any raster package (Photo, PS, PSP, Gimp, etc), you can take that pixel information and export in a format that supports a specific dpi for print.  We just need to know previously the pixels needed for a print of X inches or centimeters, and Y dpi (and color profile and etc, of course). So, if you make that calculation to guess the needed total pixels, you're good to go and work in 75dpi. For example, that it has to be a canvas of 6500x4500 pixels (just an example), then I would try to work with that and 75 DPI. The reason is because the dpi value might be messing up internally things, some bug, something. And you don't need the setting, at all. The screen always works at retina PPI (which is really high), so, no need to worry about it, we only need to work with the total pixel dimensions required for the size in cms (ie 21x27 cms) and planned DPI (ie: 300dpi) for the final print output (if is it to be printed, if not, the dpi wouldn't matter/make no sense). That's it. Hence the needed initial calculation, any image/size/resample dialog allows that automatic calculation, also in Photo-desktop.

So, by just working on the needed actual pixels (ie, 6000x3500 or whatever) and 75dpi,  we would get to know if is it the "DPI number" what is causing some conflict to the app, not the actual memory size of the file, brushes settings or anything (eliminating factors). And you can definitely work with same level of detail, just in the actual pixels amount needed but "setting it as 75 dpi", to confirm if the software has no struggle this way. That's what I'd do, definitely, in this scenario. And if it works, I'd work so until a fix comes.

In the meantime it gets examined (as the team is aware), I would first try what I suggested above, and if it does not work, well, in case it helps you, and I don't know how much of it can translate to iPad, but at least on desktop versions, this is what I learned through the years painting with Affinity Photo:

- Accumulation + Flow left as being affected both by the pen's pressure sensitivity do produce lag in certain cases (quite often). So, I leave only flow affected by pressure, as anyway, it's what I care about for a painterly feel (it makes also things more controllable for me) and in my experience tends to help with better blending.

- The "spacing" value can affect HUGELY the brush performance (not only in Affinity apps).

- Strangely enough, hardness (a bit slower if  "too soft") does accept performance. But IMO quite more slightly than any of the previous in this list. I've had no problems at all for a while with things like a 900 px brush on a 5.000x5000 px canvas, with any hardness value, but that might be because a) desktop version with many cores and a lot of RAM b) if things are now much more GPU accelerated in Affinity, my nvidia 3060 might be helping a lot, there, while in the iPad is just graphics integrated in the CPU (I know, this gives no problems in other apps).

- Size affected by pressure, surprisingly, not really or not too much: I can have it and flow both affected by the pen pressure, and work comfortably unless using huge brushes and/or really large canvases.

- In general, I simplify brushes, and I don't set anything else affected by pressure other than flow and/or size.

- Unrelated to iPad, but Windows INK and Open CL acceleration have typically affected badly, in my experience (some iOS feature could affect, who knows).

- Smoothing/line stabilizer affects the natural brush response, for obvious reasons.

- "Wet edges" used to add quite some lag to my brushes (not sure if in newer versions, as it has been a while since I used that or left that checked in the top bar(I always disable it)).

- Having other apps working at the same time, even if just "not closed" (in the background), could affect dramatically painting experience, so I am sure to "close all" before getting into a painting session.

- For the same reason, other utilities, but system based, I keep that to a bare minimum while drawing or painting.

- How you set Affinity's preferences, specially the areas "performance", "tools" and "interface" are absolutely vital for fluid painting, at least on desktop, again, I know the iPad version is way different, I've never seen their preferences screens, even. But on the desktop I do need to disable Open CL, enable my GPU as renderer (I guess here would be Metal, the thing that relates with the part dealing with graphics on the iPad, and  never leaving there "WARP" (software renderer)). Never setting "Windows Ink" (it produces instability on my end, and performance problems for painting), but "High Precision" instead. Assigning enough RAM in preferences (I assign more than it comes by default, but I am never using other app while painting), and reducing a lot the number of UNDOs in that preference screen (I only had 20 in previous apps to Affinity, so here I set something like 30 to 70 undos, not the big number that comes by default, but that's me). But maybe nothing of this exists on the iPad.

 

[SrPx]

...Also, try to disabling all snapping functions, just in case (the magnet icon).

[Lewisflakes]

2 hours ago, SrPx said:

Yep... I'm familiar with those, the straight lines (where there should be a continued curve) happened before, in previous versions (not anymore) of Affinity desktop. It was indeed common at some point of elder versions. I have not seen that since a relatively old update of 1.x, though (on desktop).

[ There might be a bug... I just like to discard everything else, first. As if it is anything else, it would have a fast solution. ]

But that's why I also recommended setting higher spacing value. You said it did not improve... Did you try with a very wild value, like 25% (instead of the usual 5% or 6%).  Kind of to see if it's a problem of performance, or is it something else.  I'm just trying to eliminate factors or hunt down why is it not able to catch up. It might even be that you are drawing the circles at an insane speed, but I doubt that... (I have noticed some old Huion and XP-Pen pen tablets/displays had issues in making fast circles, not the case with Wacom (I have Huion and Wacom devices).

"I've tried 2723x2048px @264DPI. It's not as bad as 1920x1080px @300DPI"  I don't know what would be your take with a result like this, but this is what I find most shocking. It's more pixels, more information to catch up... And yet it's working better in the one with more pixels. Still, the way we are talking about it does not make much sense (the DPI without referring to a physical size, in measures, of the document).

The DPI (probably should say ppi) is only a way of dealing with print outputs. But really all we should care is about total pixel dimensions. As later on in Photo, or on desktop in any raster package (Photo, PS, PSP, Gimp, etc), you can take that pixel information and export in a format that supports a specific dpi for print.  We just need to know previously the pixels needed for a print of X inches or centimeters, and Y dpi (and color profile and etc, of course). So, if you make that calculation to guess the needed total pixels, you're good to go and work in 75dpi. For example, that it has to be a canvas of 6500x4500 pixels (just an example), then I would try to work with that and 75 DPI. The reason is because the dpi value might be messing up internally things, some bug, something. And you don't need the setting, at all. The screen always works at retina PPI (which is really high), so, no need to worry about it, we only need to work with the total pixel dimensions required for the size in cms (ie 21x27 cms) and planned DPI (ie: 300dpi) for the final print output (if is it to be printed, if not, the dpi wouldn't matter/make no sense). That's it. Hence the needed initial calculation, any image/size/resample dialog allows that automatic calculation, also in Photo-desktop.

So, by just working on the needed actual pixels (ie, 6000x3500 or whatever) and 75dpi,  we would get to know if is it the "DPI number" what is causing some conflict to the app, not the actual memory size of the file, brushes settings or anything (eliminating factors). And you can definitely work with same level of detail, just in the actual pixels amount needed but "setting it as 75 dpi", to confirm if the software has no struggle this way. That's what I'd do, definitely, in this scenario. And if it works, I'd work so until a fix comes.

In the meantime it gets examined (as the team is aware), I would first try what I suggested above, and if it does not work, well, in case it helps you, and I don't know how much of it can translate to iPad, but at least on desktop versions, this is what I learned through the years painting with Affinity Photo:

- Accumulation + Flow left as being affected both by the pen's pressure sensitivity do produce lag in certain cases (quite often). So, I leave only flow affected by pressure, as anyway, it's what I care about for a painterly feel (it makes also things more controllable for me) and in my experience tends to help with better blending.

- The "spacing" value can affect HUGELY the brush performance (not only in Affinity apps).

- Strangely enough, hardness (a bit slower if  "too soft") does accept performance. But IMO quite more slightly than any of the previous in this list. I've had no problems at all for a while with things like a 900 px brush on a 5.000x5000 px canvas, with any hardness value, but that might be because a) desktop version with many cores and a lot of RAM b) if things are now much more GPU accelerated in Affinity, my nvidia 3060 might be helping a lot, there, while in the iPad is just graphics integrated in the CPU (I know, this gives no problems in other apps).

- Size affected by pressure, surprisingly, not really or not too much: I can have it and flow both affected by the pen pressure, and work comfortably unless using huge brushes and/or really large canvases.

- In general, I simplify brushes, and I don't set anything else affected by pressure other than flow and/or size.

- Unrelated to iPad, but Windows INK and Open CL acceleration have typically affected badly, in my experience (some iOS feature could affect, who knows).

- Smoothing/line stabilizer affects the natural brush response, for obvious reasons.

- "Wet edges" used to add quite some lag to my brushes (not sure if in newer versions, as it has been a while since I used that or left that checked in the top bar(I always disable it)).

- Having other apps working at the same time, even if just "not closed" (in the background), could affect dramatically painting experience, so I am sure to "close all" before getting into a painting session.

- For the same reason, other utilities, but system based, I keep that to a bare minimum while drawing or painting.

- How you set Affinity's preferences, specially the areas "performance", "tools" and "interface" are absolutely vital for fluid painting, at least on desktop, again, I know the iPad version is way different, I've never seen their preferences screens, even. But on the desktop I do need to disable Open CL, enable my GPU as renderer (I guess here would be Metal, the thing that relates with the part dealing with graphics on the iPad, and  never leaving there "WARP" (software renderer)). Never setting "Windows Ink" (it produces instability on my end, and performance problems for painting), but "High Precision" instead. Assigning enough RAM in preferences (I assign more than it comes by default, but I am never using other app while painting), and reducing a lot the number of UNDOs in that preference screen (I only had 20 in previous apps to Affinity, so here I set something like 30 to 70 undos, not the big number that comes by default, but that's me). But maybe nothing of this exists on the iPad.

 

Thanks for the elaborate answer. I've tried an 1920x1080px document and a basic non-pressure round brush with various spacing, flow and accumulation percentages and none gave a difference. All failed at 300DPI. None of the settings you mentioned were turned on (smoothing, snapping, stabilizer, wet edges, assistant).

Drawing at an incredibly slow speed does seem to work, no straight edges there, but drawing that slowly is not workable.

I've mentioned this previously, but 75DPI at higher resolution document sizes also give those straight lines, though not as bad as 1920x1080px @300DPI. So still unworkable I'm afraid.

And indeed, very strange that I get better results at 1200DPI than at 300DPI with same document dimensions. Doesn't make much sense!

[SrPx]

All that is very shocking indeed.

Happens even with 200% spacing (which basically is dashed lines), no freaking way spacing affects in any way here, then. But that when you increase pixel dimensions (ie, from 1920x1080px to 3000x3000px) but keeping same 75 dpi, then you notice more the problem, that demonstrates that there's indeed a difficulty in "catching up" for the app/hardware, even if as well there's another kind of problem.

The shock is partly because I have nothing of this happening on my PC (R9) neither my laptop (intel 12700h), both with the 3060, Windows 10 and 11, and having installed both v1.x and v2.x on each system, as I used to like doing that (but fully moved to 2.x now) for compatibility with old projects, until I finished them all. 

I can only think of something in your specific Pencil or tablet, or a specific combination of  them with Affinity. Would be interesting to know if other iPad users are having this exact problem in Photo and iPad Pro 12.9.   Whether if  they do or don't, also to know the exact version of Photo that they are using, and their tablets' and pencil generation. Well, you have said it happened to you with v1 and hoped to be better with v2, but it's not getting better. All with the same iPad Pro and Pencil.

It would be interesting to know if Stokerg or others in the team would be able or not to replicate it specifically with an iPad Pro 12.9", but 2020 version, like yours, and also with The Pencil version 2. As any difference in that, could end up with it not being replicated, if the incompatibility is among the 2020 version (or the pencil v2) and Affinity apps, apparently BOTH v1.x and v2.x versions of Affinity (it definitely is worth a deep look, as that's too much).

The pen works perfectly in your non Affinity apps (csp, etc), so right now I can only think of a special incompatibility or bug, driver issue, etc between the iPad Pro 12.9 2020 version + Pencil v2,   and Affinity software. It's kind of by elimination, indeed.

I would not be surprised if the Affinity Team is using the most modern/recent model available, 6th or 5th generation (2022 and 2021), and then that's why they can't replicate it... (4th is your 2020 version, I believe).

The possibility of a faulty hardware still could be happening, but not being triggered/detected on CSP or other software, though sounds more of a special software app incompatibility with a specific model.  Yet though, I had a Wacom pen that after some time went the way of the Dodo, as even the best electronic devices do that after very long years of full day use, had to buy a pen replacement on Amazon. But yours keeps drawing fine on other apps.

[ One VERY crazy idea would be if it happens like has happened in some cases before with some classic drawing tablets: proximity of powerful electromagnetic sources (even just electric stuff, as that can induce electromagnetic fields; but I don't believe you have a vendor machine besides you. Unhealthy as heck) can affect the tracing of a digital pen...it has been known to introduce wobble and other issues. And not every app being equally sensitive to that. A physical issue in the pen or tablet (it happens, but rarely) is less likely here when other apps are working fine. But if Affinity uses more the "gpu" part, uses the hardware differently (CSP is all about CPU), then , who knows ].

But yeah, shocked. Mostly as the experience on desktop (on my end, dunno anyone else's) is smooth as butter, just comparable to Clip Studio, Krita, etc.

Let's see if something else comes from testing in the devs' side with an specific 2020 12.9 iPad Pro model and the pencil v2... I'm out of ideas.
 

[Lewisflakes]

7 hours ago, SrPx said:

All that is very shocking indeed.

Happens even with 200% spacing (which basically is dashed lines), no freaking way spacing affects in any way here, then. But that when you increase pixel dimensions (ie, from 1920x1080px to 3000x3000px) but keeping same 75 dpi, then you notice more the problem, that demonstrates that there's indeed a difficulty in "catching up" for the app/hardware, even if as well there's another kind of problem.

The shock is partly because I have nothing of this happening on my PC (R9) neither my laptop (intel 12700h), both with the 3060, Windows 10 and 11, and having installed both v1.x and v2.x on each system, as I used to like doing that (but fully moved to 2.x now) for compatibility with old projects, until I finished them all. 

I can only think of something in your specific Pencil or tablet, or a specific combination of  them with Affinity. Would be interesting to know if other iPad users are having this exact problem in Photo and iPad Pro 12.9.   Whether if  they do or don't, also to know the exact version of Photo that they are using, and their tablets' and pencil generation. Well, you have said it happened to you with v1 and hoped to be better with v2, but it's not getting better. All with the same iPad Pro and Pencil.

It would be interesting to know if Stokerg or others in the team would be able or not to replicate it specifically with an iPad Pro 12.9", but 2020 version, like yours, and also with The Pencil version 2. As any difference in that, could end up with it not being replicated, if the incompatibility is among the 2020 version (or the pencil v2) and Affinity apps, apparently BOTH v1.x and v2.x versions of Affinity (it definitely is worth a deep look, as that's too much).

The pen works perfectly in your non Affinity apps (csp, etc), so right now I can only think of a special incompatibility or bug, driver issue, etc between the iPad Pro 12.9 2020 version + Pencil v2,   and Affinity software. It's kind of by elimination, indeed.

I would not be surprised if the Affinity Team is using the most modern/recent model available, 6th or 5th generation (2022 and 2021), and then that's why they can't replicate it... (4th is your 2020 version, I believe).

The possibility of a faulty hardware still could be happening, but not being triggered/detected on CSP or other software, though sounds more of a special software app incompatibility with a specific model.  Yet though, I had a Wacom pen that after some time went the way of the Dodo, as even the best electronic devices do that after very long years of full day use, had to buy a pen replacement on Amazon. But yours keeps drawing fine on other apps.

[ One VERY crazy idea would be if it happens like has happened in some cases before with some classic drawing tablets: proximity of powerful electromagnetic sources (even just electric stuff, as that can induce electromagnetic fields; but I don't believe you have a vendor machine besides you. Unhealthy as heck) can affect the tracing of a digital pen...it has been known to introduce wobble and other issues. And not every app being equally sensitive to that. A physical issue in the pen or tablet (it happens, but rarely) is less likely here when other apps are working fine. But if Affinity uses more the "gpu" part, uses the hardware differently (CSP is all about CPU), then , who knows ].

But yeah, shocked. Mostly as the experience on desktop (on my end, dunno anyone else's) is smooth as butter, just comparable to Clip Studio, Krita, etc.

Let's see if something else comes from testing in the devs' side with an specific 2020 12.9 iPad Pro model and the pencil v2... I'm out of ideas.
 

I've found this other post by @ZufDraw , which seems to be similar with the long-standing brush-issue I've encountered on the iPad.

Thanks anyway for trying to help! Hopefully anybody of the team (@stokerg?) might come with a reply soon?
 

 

 

[Lewisflakes]

Update: I've tried drawing circles with my finger, rather than with the Apple Pencil 2, and the problem remains the same. This most likely rules out that the problem stems from the Apple Pencil 2.