Hey all,
I was trying to get into downsampling / DREZ and I’m ab bit confused. Let’s say I want to use this feature with N64 emulation and Duimon’s shaders. What should I do?
What internal upscaling should I select in the N64 Emulator (using Mupen64 core with ParaLLEL RDP)?
What should I select in the downsampling / DREZ setting in Mupen?
Should I then use the Duimon DREZ preset on top of mupens downsampling?
Thx for the help!
Read the section in the second post about DREZ. If you still have questions, ask them after.
Yeah, I read the section, of course. These are my questions after reading that. Sorry, I know they might be at bit dumb, haha.
Alas with wocrashed I have nothing, I’ve already searched. Nothing is mentioned, I don’t have a partial memory image created during the crash, which is surprising. When the blue screen appears the pc doesn’t restart and stays on the blue screen mentioning the error.
I store my roms on my internal ssd m2 samsung 980 pro 2to, I thought the memory was saturated by the shader, so as a precaution I cleaned the DXCache and NVIDIA GLCache, as well as the ram memories.
The problem doesn’t occur often, but sometimes I get the impression that something is saturated or incompatible at some point.
I’ve left avx512 enabled in auto in the bios since the start of my Windows installation, so I don’t know if this might have something to do with the abnormal shader behavior.
No worries.
If you are using a core that has both upscaling and downsampling, and are using both, then you should not use the DREZ presets.
The DREZ are for cores that have upscaling, but no downsampling.
There are two reasons for using the DREZ presets.
The first is for general smoothing and visible scanlines. In this case you want to use a high internal resolution, and a “Native” DREZ. (240p for older systems and 640p for newer systems like N64 and Dreamcast.)
The second is for a very smooth result when scanlines aren’t a priority. In this case use an internal resolution of at least 1080 and a 1080p DREZ.
In the last case you could still use 240p res fake scanlines. Here is an example.
Beetle PSX HW at 8x internal resolution, using a 1080p DREZ with 240p integer scale fake scanlines.
Hey, thx for clarifying!
So I messed around with Flycast, since it does not have internal downsampling and I ran into issues.
I have the internal resolution set to 1440p. Now if I use the 1080p DREZ preset, everything looks crisp and fine, but if I want to use a DREZ preset for a lower resolution, something is off.
Since the Dreamcast had a 480p resolution, I tried a 480p DREZ preset, but I get a weird moire effect instead of straight scanlines.
The same miore effect happens if I set the internal resolution of Flycast to 480p and then use your regular (non DREZ) preset.
Any clue on what to do to get straight scanlines? I’m on a 1080p TV if that’s important.
EDIT:
Some further testing has revealed the following:
You can try to set the CRT Curvature Scale Multiplier: 0 = Less Moire to 0 to remove curvature from the image while leaving the bezel the same.
And moire is definitely more visible at 1080p vs 2160p
Thanks for the suggestion. Just tried that, but this looks really weird. The scanlines get really thick and look like they are just placed on top of the screen.
As I said, I don’t have the miore problem in emulators that support downsampling (mupen and swanstation). If I downsample here and use a megabezel preset, the scanlines are perfect and there is no miore distortion effect present.
If I understood correctly, these DREZ presets just don’t work on 1080p displays without miore distortion?
I’ll have to try them at 1080. Which DREZ presets are you trying?
Can you post images?
It really helps to see what you are seeing, it’s hard to know what is going on without some visuals.
I’ve tried this with Flycast: Dreamcast-[DREZ]-[480p]-[ADV]-[Guest]-[Bezel].slang
and this with Dolphin: Gamecube-[DREZ]-[480p]-[ADV]-[Guest]-[Bezel]
But keep in mind this also happens with the regular (non DREZ) presets if I chaange the internal resolutions within the emulators to native.
It does NOT happen with mupen or swanstation’s interal downsampling + your (non DREZ) presets.
I tried doing that, but I’m too dumb it seems. If I just take a screenshot and save it somewhere, I can only see the bezel without the actual screen. How do I take a screenshot like that?
So you can turn on gpu snapshot in Retroarch, and do the snapshot item in the quick menu, or you need to ALT-Tab back and forth to retroarch before taking a Windows snapshot, because if you are in fullscreen mode the framebuffer Windows had only updates when you change focus between the desktop and back to retroarch
Flycast. Internal res at 1440 using the same DREZ preset at 1080.
I don’t see any moire at all.
Looks really nice. 
Same with GameCube.
Maybe a bit of moire when the screen goes white.
Honestly, by far the biggest reason to use DREZ is to keep Retroarch from crashing using very high internal resolution. 1440 on Flycast would probably be OK. Most people run into issues at 4x scaling or higher.
Then you can use reduce scanline Opposite Direction Multiplier so you can see the scanlines.
Here is Flycast with these settings.
This is at 4k but in person the results are very similar to the DREZ.
Just for the hell of it, here is Dolphin at 6x internal res, using a 1080 DREZ, and enough Opposite Direction Multiplier to give it the 480p look.
6x internal res would require DREZ to not crash.
Hey there,
I was able to get some screenshots:
This is Dreamcast with 1080p DREZ: No moire:
These are examples of Dreamcast 480p DREZ with imho distracting moire. Does this look normal to you or am I doiing something wrong?
in the first 2 screenshot I can see moire in the sky in both, also in the water in the first one and on the ground in mario kart, also un-even scanlines are somehow visible. not sure about the other 2 because I’m on a 1080p display.
What’s happening here is that the 1080p derez is hitting the scanline interlace cutoff number, and therefore removing the scanlines (and moire), the 480p one is trying to show you the scanlines, and there just isn’t enough resolution at 1080p (Monitor Res).
What I would suggest is reducing the scanline interlace cutoff, when you reduce it low enough the scanlines and moire will disappear.
If you want scanlines you could increase the fake scanline opacity after following HSM’s suggestion. They don’t have curvature by default so should not produce moire.
You could also turn off the bezel curvature. AFAIK moire is mainly caused by curvature.
Does the error happen with any of the other presets? (Not a SMOOTH preset.)
The SMOOTH are pretty GPU memory demanding. It could be that at some point you are drawing too much power on that rail. If you have a faulty rail it might not show unless it is under load.
I usually keep a spare PSU lying around to test my system on a known working PSU. I also buy only one brand of modular PSU so if it fails I don’t have to run new wires.
I am really only making a guess at this point. We have never had this error reported so I’m sure it is not directly related to the shader.
Hey, thanks for clarifying!
“What I would suggest is reducing the scanline interlace cutoff, when you reduce it low enough the scanlines and moire will disappear.”
Well, the thing is that I wanted to try the DREZ stuff, because I WANT to see some scanlines, so this would defeat the purpose.
“and there just isn’t enough resolution at 1080p (Monitor Res).”
Oh, I see, so you are saying that I’d need a 4K display to show the scanlines without the moire? Is there a reason why on eg.g mupen64plus and swanstation and their internal downsampling, the scanlines show correctly without moire when using Duimon’s (non-DREZ) presets (see the mario 64 screenshot)? Are the DREZ-presets specifically made for 4K whereas the non DREZ aren’t?
@Duimon "If you want scanlines you could increase the fake scanline opacity after following HSM’s suggestion. They don’t have curvature by default so should not produce moire.
You could also turn off the bezel curvature. AFAIK moire is mainly caused by curvature."
Thanks for the suggestions, but I also want to have the curvature (I want to have it all, haha). I’m just curiuous why everything works fine with mupren64plus (internal downsampling + non-DREZ-preset), but not with Dreamcast (no internal downsampling but DREZ-preset). I mean, both have curvature, both have scanlines, but I get moire only with the DREZ presets.
