That my friend, is a very good question.
I am unsure of the answer. I also don’t know why you get more moire than I do running the same presets. I have a 4K monitor, but if I switch to windowed mode I should be using the same number of pixels as you are.
Are you using any DPI scaling in your OS?
“more moire”
So to get more info if you can turn on the resolution debug parameter (second parameter in the list) and take some screenshots
“Are you using any DPI scaling in your OS?”
In fact, I do. Since I’m on a TV screen, the DPI scale is at 125%. However, I just set it back to 100% and tried again and the moire was still present.
I did some further testing with mupen64plus, to see if the issue was not with the presets. Here is what I found:
It seems that only the 480p DREZ causes moire, which is a shame, because that’s the one I want to use, haha.
EDIT: Somehow the moire effect in the second screenshot does not look as bad as it does in person. And also, in screenshot 1 and 3, there seems to be some moire present as well that I do NOT see in person. Don’t know why. It’s weird.
It does provide some useful info, can you post one of below with the resolution debug on?
I can see from the stats that the screen height is about 900px tall, and the number of scanlines is 480,so each scanline has about 1.85px height which is not enough to resolve properly
here is the other screenshot:
mupen 64 internal downsampling + non DREZ preset --> no moire:
“I can see from the stats that the screen height is about 900px tall, and the number of scanlines is 480,so each scanline has about 1.85px height which is not enough to resolve properly”
Yeah, I though that something like this might be the case. Is there some way to fix this or is there no way around a 4K screen … or would the issue also persist with a 4K screen, but it would just be less noticeable?
EDIT: The mupen core settings are: 4x upscaling; 1/4 downsampling.
From your shots I think you meant 480p not 240p. 
Since it is a lack of monitor pixels that is causing the issue, you could try changing the mask type and/or lowering the mask intensity.
You might also want to make sure you are using “Integer scaling” in the Nvidia control panel.
hey, yeah of yourse, I wanted to write 480p. My bad. I corrected the mistake in the original post. And yes, I do use intergar scaling already:
" you could try changing the mask type and/or lowering the mask intensity"
These are settings in the shader parameters, right? How would I need to change these settings, so the monitor pixels are enough for the scanlines to resolve evenly?
You can’t, but you may be able to make it “tolerable”. You could also increase the “Integer Scale” to see if it helps.
We can “mitigate” moire but in this situation, but not eliminate it without doing away with the scanlines.
You can also adjust the “Opposite direction Multiplier” so you have fewer scanlines.
Oh man, I just found out that Swanstation DOES have the moire effect, too even though it has internal downsampling, I just diodn’t see it before. So the issue is definitely with my hardware.
So would a 4K screen eliminate moire entirely?
So if you take a look at the core res, here it’s 216px so only 216 scanlines to resolve over 900px tall, so a bit over 4 px per scanline which is why it looks good.
Ok cool, so that explains it. So isn’t it at all possible to change the screen size to make the scanlines fit perfectly?
It would certainly help. Plus you get the benefit of having enough pixels to draw a decent mask. (If you tweak the mask parameters.)
That is what I meant by this…
If you have twice as many pixels as you have scanlines it should look better. Drawing a detailed mask will still be impossible.
Here I’ve taken my “Custom_Bezel_001” 480p DREZ preset, increased the integer scale until the screen size was equal to the core output, and lowered the bezel width.
I also changed the “Opposite Direction Multiplier” from 100.00 to 75.00.
Here is a shot of a 1440x1080 white image in the image viewer core, before changing the integer scale.
Here is one after changing the integer scale.
And one after adding the lower Opposite Direction Multiplier.
The moire gets less with each change.
I guess my point is that we can mitigate the moire. But the easiest long term solution would be to use a 4K display.
TBH, I don’t have a 4K TV (I do have a pair of 4K monitors.) so I know it’s not an easy thing to suggest.
Yes you can turn on the integer scaling in the shader parameters and increase the max screen size until it jumps to 2x.
You will still have problems if you are still trying to have 480 scanlines with curvature though
I can see from other posts that there is a way to turn off scanlines. How is that done? There are a lot of settings. I can’t figure it out.
You have to be using the ADV GDV presets to use the “no scanline” mode (It took me a few to figure that out).
You can also lower the “Interlacing and Fake Scanlines Trigger Res”. If for some reason 100.00 is not low enough (Very low res core.) you set it to 100.00, save a preset, and manually set it lower by editing the preset file.
The option is in the STD GDV also.
I have been on a pretty cool adventure lately.
It all started with my lovely wife and I doing a little spring cleaning in the summer. While organizing the shelves in our furnace room I found this.
This may bring back a few memories for some of you. For me it goes a bit deeper.
I was never keen on Microsoft Windows back in the day. I used GeoWorks (PC/GEOS) for years before I was forced to run Windows.
It just so happens that AOL was bundled with GeoWorks years before it became the Windows phenomenon we all remember.
So I did my best to give my lovely wife a taste of what I had been through. Here are the results.
GeoWorks 1.2 with AOL.
GeoWorks 1.2 AOL.
Then we have the newer versions.
GeoWorks 2.0
And the now open source BreadBox Ensemble.
BreadBox Ensemble 2.5d
And then I went further back in time and ran Geos 2.0.
GEOS 2.0 C64
GEOS 2.0 C128
Sadly we don’t have a 128 preset yet. Hopefully @TheNamec won’t keep us waiting too long. 
Anyway… it was a very fun adventure.
I used GeoWorks in 1991, long before the Internet, and AOL was life changing compared to CompuServe and Bulletin Boards.
GeoWorks didn’t have many games but you could create DOS shortcuts and run DOS games.
It also had WYSIWYG printing many years before Windows got True Type fonts. (Although Adobe Type Manager was available pretty early in Win 3.0.)
