Median and Blur brush no effect

[A--]

WIndows 11 on a Dell XPS 15 with factory settings for system graphics (high DPI)

Brushes preview as transparent circles and nothing happens for median brush, possibly very faint effect on blur. So faint, I'm not 100% positive I can see it, even when I do an undo to test the effect.

Wasted a lot of time with this because I wasn't sure whether it really was not working at first or just some wrong setting somewhere. Clicking vs. Dragging seemed to make no difference.

Search shows this issue may have been discussed with dates from 2022 and early 2023. If the same, looks like it's unresolved.

[walt.farrell]

If you check the application Settings, Performance, do you have Hardware Acceleration (OpenCL) enabled?

If you do, does disabling and restarting the application help with this issue?

Also, what Brush have you chosen from the Brushes panel for use with these Tools?

[A--]

This was the first time I used the median brush and in a new installation. I didn't know I had to make a selection before using it. None of the other tools ever required making a selection. I clicked on More and got a panel that had an entry "no associated tool". I selected Median brush, and now I observe an effect. Its more subtle than I expected, but then, I've never used it before.

The scale over which the median effect is applied seems fixed and not dependent on brush size. The latter only seems to affect which part of the image is modified at once.

With the selection the preview starts out normal, but after first application goes back to transparency.

Interestingly, "undo" will reset that behavior, so it's almost like it's driven by a parameter that's saved on the undo stack.

As for HW acceleration it was on, but turning it off seems to only affect the preview. Seems curious that on a modern laptop this feature would have to be disabled to make the program work. What's the downside of leaving this disabled? What's the upside, other than this one brush preview.

Final observation: it seems weird to require a user selection on a hidden panel before being able to use a tool from the toolbox.

[walt.farrell]

1 hour ago, A-- said:

I didn't know I had to make a selection before using it.

You should specifically select the brush you want for any tool whose name is "something" Brush Tool. You don't have to, but then you can't be sure what you're working with.

1 hour ago, A-- said:

Final observation: it seems weird to require a user selection on a hidden panel before being able to use a tool from the toolbox.

It's a Brush. Which Brush would you like it to choose automatically, and how reproducible would you like your workflow to be?

[A--]

Quote

It's a Brush. Which Brush would you like it to choose automatically, and how reproducible would you like your workflow to be?

When I click on a named brush on the tools palette in a new installation, I don't expect to have that button disassociated from anything. What I would expect is to get some factory defaults. Apparently those are applied for the regular paint brush, because I am free to modify it, but I do get some defaults that make it act like, you get it, a paint brush.

Why should the median brush be different?

Some of the values displayed by the UI were clearly defaulted, like the 80% value. But there's no visual indication that the program thinks that "no tool is associated" with this tool palette button. I also don't get the logic of associating a different type of tool to something that's named one way in the palette. What if I select "erase brush". Would that then associate the erase function with the palette item that uses the median brush icon?

Sorry, there's some thinking here that I'm not getting. I'm not stepping up and saying "gimme some brush, any brush". I'm selecting something that calls itself the median brush.

[GarryP]

Unless I’m mistaken, it sounds to me like you might be getting the Brush Tools mixed up with the Brushes.

Some of the Tools on the Tools Panel have the name “<something> Brush Tool” and these Tools use Brushes to do their job.
The Brushes that the Brush Tools use are selected from the Brushes Panel.

When you want to use a Brush Tool you first select the Tool and then you can, optionally, select a Brush to use with that Tool.
If you do not select a Brush then the software will use either the Brush that was last used by any Brush Tool or the last Brush that was used with that specific Brush Tool, depending on the settings in the Assistant.

There are options in Settings/Assistant where you can tell the software whether you want to share Brushes between Brush Tools or not.
You can choose whether the software keeps using the Brush you were last using with any Brush Tool or whether you want to use different Brushes with different Brush Tools.

Remember, a Brush Tool is not in itself, and does not ‘have’, a Brush.
You use Brushes with the Brush Tools and different Brushes have different effects with different Brush Tools under different circumstances.

A Brush you are using with a Brush Tool may not give the effect that you are looking for as it might not have been designed to work with that particular Brush Tool in the way that you might want.
In these cases you will need to experiment with using different Brushes to see which work best with a particular Brush Tool to achieve the effect that you want.

I hope this helps to clear things up a bit.

[walt.farrell]

2 hours ago, GarryP said:

Remember, a Brush Tool is not in itself, and does not ‘have’, a Brush.

Well, in a sense it does. A fresh install of an Affinity app (or one with the brushes "factory reset" via Ctrl run-up) has a default brush that is used for each brush tool.

Weirdly, it is not a brush that is actually supplied with the applications, and not a brush that you can get back to unless you thought to save it that first time, or unless you do another factory reset or fresh install.

 

[A--]

OK. So, on a new install, if I click on the inpainting brush tool I get something that does inpainting, but when I click on the median brush tool, I get something that performs no action. That's the point that didn't make sense.

Also, it's nice but not very intuitive if I can associate an undo brush with the paintbrush tool. If I understood that correctly.

[walt.farrell]

23 hours ago, A-- said:

I clicked on More and got a panel that had an entry "no associated tool". I selected Median brush, and now I observe an effect. Its more subtle than I expected, but then, I've never used it before.

You should not need to have an associated tool. And I can make it work without one. Perhaps you had a subtle effect before, that you didn't notice. Or, on the other hand, for me, it's also important to have Hardware Acceleration (OpenCL) disabled in the application Settings, Performance. With it enabled, I have no effect (and the brush preview is empty). With it disabled I have a subtle effect.

45 minutes ago, A-- said:

Also, it's nice but not very intuitive if I can associate an undo brush with the paintbrush tool. If I understood that correctly.

I'm not sure there's an "Undo Brush". There is an "Undo Brush Tool", which uses a Brush to paint over pixels that you want to restore to an earlier state, and you can pick which Brush you want to use.

Or, you could take a particular Brush and associate it with the Undo Brush Tool, such that when you choose that Brush the application switches to the Undo Brush Tool automatically. That seems like a very odd capability, unless you had a very special brush you wanted to use for Undoing and for nothing else. But that's how the Association capability works in general. It's to allow you to choose a Brush and have that action also choose a Tool for you.

I think it's important to get the terms right. A Brush is a specific set of characteristics (hardness, size, flow, opacity, ...) that control how paint is applied; a Brush Tool is a Tool that performs a specific function, using a Brush to control how that function affects the pixels. (That's still more confusing than I'd like it to be, and probably wrong in some way. But it's important to be clear whether you're talking about a Tool or a Brush that is used by a Tool.

[NotMyFault]

On 1/12/2024 at 12:39 PM, A-- said:

Brushes preview as transparent circles and nothing happens for median brush

When the brush preview shows a transparent circle on a non-transparent pixel layer, this is a bug which occurred multiple times. It could be related to hardware acceleration/ gpu driver, or using an outdated Affinity release.

[NotMyFault]

On 1/12/2024 at 12:39 PM, A-- said:

possibly very faint effect on blur. So faint, I'm not 100% positive I can see it, even when I do an undo to test the effect.

The blur effect is barely noticeable, this has been raised as issue multiple times before. 
I recommend to not use the blur brush, it is next to useless in my experience.

Instead, use a non-destructive workflow:

• add a blur live filter of you choice. 
• set a suitable strength, e.g. 2 to 8px radius
• zoom in to exactly 100%. This is really important 
• invert inherent mask of filter
• choose brush tool
• select a basic round brush (one with hard edge, not a soft one)
• choose color white
• set opacity to 25%
• Set hardness to 80%
• paint in mask

This gives far better control over strength of effect and allows to reduce or remove blur any time later if overdone or applied in wrong area.

 

 

[A--]

8 minutes ago, NotMyFault said:

When the brush preview shows a transparent circle on a non-transparent pixel layer, this is a bug which occurred multiple times. It could be related to hardware acceleration/ gpu driver, or using an outdated Affinity release.

New installation on new hardware.

H/W acceleration is the apparent cause for the transparent circle, but what I don't get is why this feature would not be working in an up-to-date configuration using the latest chipsets and drivers. Is it something that works only on the Mac? Is it a useless feature and should have been disabled by default?
 

Or should the app be able, by now, to recognize when H/W acceleration should be turned off during install.

Having this happen out of the box is a bug.

[A--]

7 minutes ago, NotMyFault said:

The blur effect is barely noticeable, this has been raised as issue multiple times before. 
I recommend to not use the blur brush, it is next to useless in my experience.

Instead, use a non-destructive workflow:

• add a blur live filter of you choice. 
• set a suitable strength, e.g. 2 to 8px radius
• zoom in to exactly 100%. This is really important 
• invert inherent mask of filter
• choose brush tool
• select a basic round brush (one with hard edge, not a soft one)
• choose color white
• set opacity to 25%
• Set hardness to 80%
• paint in mask

This gives far better control over strength of effect and allows to reduce or remove blur any time later if overdone or applied in wrong area.

 

 

Useful tip. I don't usually use a blur brush. But when I mask off a blurred layer, the non-blurred part of the image "leaks" at the edges. Say, I'm trying to blur the background around a white foreground item. This produces a white halo. Is that different with the live filter?

[NotMyFault]

2 minutes ago, A-- said:

Useful tip. I don't usually use a blur brush. But when I mask off a blurred layer, the non-blurred part of the image "leaks" at the edges. Say, I'm trying to blur the background around a white foreground item. This produces a white halo. Is that different with the live filter?

When you invert the mask of the filter and paint in only small areas with a brush width distance to the edges this does not impact the result in any way. 
 

If you want to blur the full area, you may activate „protect alpha“, but the edges will always look slightly different. 

[NotMyFault]

10 minutes ago, A-- said:

Or should the app be able, by now, to recognize when H/W acceleration should be turned off during install.

It is complex. Using HW acceleration to achieve highest performance is a bit like formula 1 racing, but on unknown race tracks which could change the surface conditions and layout after you finished your car and fitted tires for dry wether.

Affinity actually compiles a GPU program from source code live for every filter or adjustment you add during editing. They cannot test every possible combination of GPU and GPU driver version, and especially newest version could be a challenge.

[A--]

38 minutes ago, walt.farrell said:

You should not need to have an associated tool. ...

I think it's important to get the terms right. A Brush is a specific set of characteristics (hardness, size, flow, opacity, ...) that control how paint is applied; a Brush Tool is a Tool that performs a specific function, using a Brush to control how that function affects the pixels. (That's still more confusing than I'd like it to be, and probably wrong in some way. But it's important to be clear whether you're talking about a Tool or a Brush that is used by a Tool.

Pick median brush TOOL. Out of the box, nothing happens. Go to "MORE".  This opens the "Brush Selection" panel. On a fresh install, this panel has all sorts of default values. However, when you look at "associated tool", that field says "no associated tool".

That's a bug, because I am reaching it from the the tool I just selected, and it should have some factory default settings.

Also, what happens when I select a different associated tool from that panel? I guess, it's a generic panel, so even though I accessed it from the median brush TOOL I could use it to edit the brush used with some other tool instead. That's weird. (I guess it doesn't change the function of the tool, although I did have to change to make a selection of Median Brush Tool to enable the tool. That's a step not needed for any other tool and seems a bug.

(PS: I'm fine with the reason for wanting a specific brush for each tool, but to have no apparent default seems broken).

[A--]

2 minutes ago, NotMyFault said:

It is complex. Using HW acceleration to achieve highest performance is a bit like formula 1 racing, but on unknown race tracks which could change the surface conditions and layout after you finished your car and fitted tires for dry wether.

Affinity actually compiles a GPU program from source code live for every filter or adjustment you add during editing. They cannot test every possible combination of GPU and GPU driver version, and especially newest version could be a challenge.

Then the proper thing to do is to leave that off during install, because letting users run into broken tools is a bug.
The app knows what drivers are present on the system (that info is echoed when H/W acceleration is enabled).
I've had several PCs (top of the line) and none worked with H/W acceleration. My suspicion is that this feature really only works on Macs.

[walt.farrell]

2 minutes ago, A-- said:

Pick median brush TOOL. Out of the box, nothing happens. Go to "MORE".  This opens the "Brush Selection" panel. On a fresh install, this panel has all sorts of default values. However, when you look at "associated tool", that field says "no associated tool".

That's a bug, because I am reaching it from the the tool I just selected, and it should have some factory default settings.

No, you're using a default brush, with default characteristics, and it has no associated tool because it doesn't really exist. You cannot pick it from the Brushes panel, for example. Associated Tool is used for brushes that exist in the Brushes panel, to cause a switch to that Tool if you pick that Brush.

[A--]

Just now, walt.farrell said:

No, you're using a default brush, with default characteristics, and it has no associated tool because it doesn't really exist. You cannot pick it from the Brushes panel, for example. Associated Tool is used for brushes that exist in the Brushes panel, to cause a switch to that Tool if you pick that Brush.

OK, so there's a "magic" default brush. However, it actually appears to be doing nothing for some tools, but works fine for others, and that remains a bug.

[walt.farrell]

3 minutes ago, A-- said:

OK, so there's a "magic" default brush. However, it actually appears to be doing nothing for some tools, but works fine for others, and that remains a bug.

If you have Hardware Acceleration disabled, it will probably work for you. That's a separate issue, especially as it is not clear where the bug is. If the Hardware Acceleration option starts out Enabled, that means that you have a GPU whose driver says it supports all the OpenCL functions needed by the Affinity applications. 

If something doesn't work at that point it may be because

• the GPU driver or GPU has a bug in the processing of the functions it claimed to support. We have seen many cases reported where a function worked in Affinity, then the user updated the GPU drivers, and the function failed with the newer driver. Either reverting to an older level of the driver, or waiting for a newer level, then has restored the function for those users. To me, that indicates that some (perhaps many) of these problems are with the drivers. But it is time-consuming for Serif to prove that, and contact the GPU manufacture, and demonstrate it to them so they can fix their drivers.
  or
• because there's really a bug in the Affinity code. But I've seen enough cases that have shown it's a driver problem that I can't definitely conclude that any of them are Affinity issues.

Often, most functions work fine, and only a few have problems. So usually, for most users whose GPU/driver claims to support the functions, having them enabled is better. But then for some users some set of functions will have problems. And for other users a different set will have problems. So each user basically has to figure out for themselves, and just recognize when something is wrong and try turning off the Hardware Acceleration to see if that fixes it.

And yes, that's annoying. But if it were disabled from the start, each user would need to either accept that their performance is worse than it could be, or do the experimentation by turning it on and seeing what works and what doesn't.

[A--]

Thanks for the explanation. However, I come to the opposite conclusion. Apparently the support for H/W acceleration is a hit or miss. That means, every user is effectively forced to "see what works and what doesn't" and to do so again after every system update (in case some affected driver has an incompatible update). That does not seem to me to be a feature that should be enabled by default. Instead, it would be more honest to label it "buyer beware" and "proceed at your own risk".

I'm also curious about the apparent lack of diagnostics to verify that the H/W acceleration actually gives compatible results. From what you describe, the most logical time to perform them would be at startup, or, as Affinity Photo seems to track the drivers, at install and when updated drivers are detected. Or, alternatively, as a manually initiated troubleshooter.

[NotMyFault]

You are free to post feature requests in the feedback section of the forum. Walt and I simply explain the current situation and try to help other forum users to solve or work around issues.

The discussion about hw acceleration issues has already filled countless threads, I’m no longer interested as every argument has been stated multiple times. Nothing against you, I’m just tired.

[A--]

No intention of tiring you out. If this is a longstanding issue it may be because there's either not a good solution, or the solution chosen is counter-intuitive. I'm a fan of the program, but not a professional artist or super-user. And I'm used to muddling through w/o bothering the forums.