Sometimes Subtract brush on a mask don't work at all

[ralphlouzon]

Hi,

I guess the attached screenshots are self-explainatory, I make a background mask which is not perfect (part of my subject is also selected). I click on substract and choose a brush: impossible to substract anything, the brush has absolutely no effect (screenshot 04, not visible but believe me!) .

If I choose to substract with the radial or gradient the mask it works fine... (screenshot 05)
What happens?

Thank you

PS: last version of LRC / MacOs 12.6

[dj_paige]

I guess the attached screenshots are self-explainatory

Not self-explanatory to me. My web browser refuses to show file attachments. If you could provide screen captures by clicking on the "Insert Photos" icon, then I can see them.

A guess without seeing your screen captures: in the brushing tool sliders, you have set either Density or Flow (or both) to zero

[ralphlouzon]

Thank you for reading dj_paige.
I resend all the screenshots and hope you will see them (they are simple JPGs). You could see that Opacity and Flow are at 100%.

I add these observations:

- Once I can substract with radial mask for instance, the substract brush works again...

- This bug doesn't appear each time, I worked on similar pictures with no issue (and exactely the same settings).

[dj_paige]

Ralph: I said "If you could provide screen captures by clicking on the 'Insert Photos' icon"

[richardplondon]

Just to make sure: when working on this new mask component layer (set to subtract) you do not want to ERASE with your paintbrush. You want to ADD painted areas - and the more painting you do, the more areas you are removing from the overall mask selection.

This is especially confusing because usually the paintbrush shows a + sign when it is adding more 'paint', and a - sign when it is removing 'paint'.

However in the special case of a mask layer that is set to Subtract action:

the + and the - symbols in the middle of the brush show reversed.

So in this context you DO want to paint with a "-" symbol in the middle of the brush - meaning, this brush will be adding on MORE (subtracting) 'paint'.

[ralphlouzon]

I acknowledge that +:- symbols can be confusing in LRC.
In that case my aim is to erase a part of a mask (Background type), I select Substract and I get indeed a brush with a "-" sign. And it works! But most part of the time... sometimes not, that's my problem.

Maybe I mess around things, if so I don't understand what.

Here other screenshots in the message body: the tool selected in the mask panel and the look of this tool on the picture. (this time it works perfectly)

[richardplondon]

In your screenshot 4, I notice the Density slider is disabled and this is characteristic of the brush being in Erase mode. But most likely, that is just a side effect of making your screenshot (perhaps pressing the same modifier key for doing that, which also switches the brush between paint and erase). But I thought I should mention it.

This does sound to me like some difficulty or variation in the brushing itself. Are you using a pressure sensitive pen, or a mouse?

I suppose if sometimes the mask was set to Add, unintentionally, instead of Subtract. Or pressing number keys while brushing (so, reducing the brush strength without meaning to). But I expect you know what you are doing in those aspects.

[ralphlouzon]

Hi Richard,

I used a mouse, and didn't press any key while brushing.

I didn't notice this density slider disabled, I noticed that it occurs rather in Intersect mode than in Substract mode... don't you agree? Maybe something happened while I made the screenshot (Command+Shift+4 on an Azerty kb), I couldn't repeat it.

Since my first post this strange thing didn't occur, as soon as I get it again I'll try to document it with a video capture.

Thank you for all the inputs

[richardplondon]

Intersect is the same thing as Invert with Subtract. So I'd expect the same logic so far as the + and - signs in the middle of the brush.

Your screenshot 4 looks as if you have begun a new brush 'layer' (mask component), but you have not done any brushing yet. The "pinceau" name is in italic text and "effacer" is black. This changes once you have started to paint. But if you only start by erasing, or anyway have not yet put on any paint, then no brush layer has really been made yet.

[bhousto90]

I would have to agree with Ralph that there is some sort of bug here.

Yes to Richard it looks Ralph has not started the brushing action as there is no visible brush pin yet,

but then there is a problem with the shown brush panel:

The Erase option is blacked out and the Density slider is also grayed out at the same time, A and B brush options are also light gray.

Any time that I worked with the Erase brush, then it would be bright text while also showing the grayed out density slider

Also the erase option is normally disabled (black text) until you have started brushing  (You cannot erase something the does not exist yet)

So in Ralph's case it seems that somehow the subtract brush is starting up without any A/B brush option selected?

Perhaps there is set of conditions that when you are editing a previous photo with the brush in erase mode then that is sticky when you start the new photo? And when Ralph uses a different masking tool it fixes the problem.

Sounds like he should start with reseting Lightroom's Preferences?

[richardplondon]

There is something strange - yes a Preferences reset seems a good idea to me. 

My own brush panel in its initial state (before doing any positive brushing) looks like this:

where my last used brush happened to be A. I can't explain how both A and B could ever be un-highlighted together. But the black disabled Erase is characteristic of the case IMO.

If you sometimes made a new subtract brush layer and did extensive erasing instead of painting (mistakenly, but IMO quite understandable) - this would be what you continued to see, and your work with the brush would have no effect. And if other times you remembered you had to paint instead of erasing, those times it would work as expected. All this would be at the least compatible, with the varying symptoms that the OP reports. Of course there may well be something else going on.

Such as, painting with NEITHER brush setup A NOR brush setup B active - which should be impossible; but if it were ever the situation due to some bug, I imagine might indeed have no visible effect on the mask!

[ralphlouzon]

I rebuilt LRC preferences. So far nothing wrong...