Achieving period-correct graphics in personal computer emulators

[Rincewind]

Happy to see this topic still going. Some valuable info here, mostly thanks to The Shader Man himself, Slim Shader, The ShaderMaster General, you know him, you love him - Boom Boom Rincewind! I'm more of a plug n play type myself that just slaps a shader onto something and hopes for the best that it looks good, and not one to fiddle with settings and configs, but if I need that kind of info, looks like this is the place to get it. Coincidentally, I have been recently looking for a good DuckStation (my newest emu obsession) shader and saw that Rincewind just happened to upload a couple here. Now if I can only figure out how to inject them into Duckstation using Reshade (which I only tried for the very first time with a recent game I was testing - My Time At Sandrock - that looked incredbly, unacceptably washed out but the Rehade preset completely fixed it. I'm beginning to think that shaders and reshade can cure cancer )

No no, DuckStation has ReShade integrated *into it*, so you can use ReShade shaders *within* DuckStation! They show up in the available shader list in the Duckstation GUI if you copy it into the appropriate folder.

So I have two variants in my repo:

1. The bog standard ReShade variants

You use these with emulators like PCSX2 as you'd normally use ReShade with modern games, so as a post-processing step. This has limitations when it comes to accurate scanline and interlacing emulation (the post-processing shader has no way of knowing about the actual internal resolution of the emulated image), but that's the best we can do.

https://github.com/johnnovak/CRT-Guest-ReShade/tree/main/ReShade


2. The Duckstation specific ReShade variants

This will give you superior result in DuckStation as the shader is aware of the native emulation resolution, can handle interlacing perfectly, and so on. *Only* use these "ReShade++" variants for DuckStation for best the results!

https://github.com/johnnovak/CRT-Guest-ReShade/tree/main/Duckstation

Also keep in mind I've only fixed the NTSC variant so far. The other two kinda work, but they have bugs. I'll do them later this year; the guy who originally converted them made some errors.

---

I will put all this info into the README of my repo because it might confuse some people, yeah...

My hope is the PCSX2 will also adapt the native ReShade format in the future, but we'll see.

About 4k, yeah with 240p content you won't see a night and day difference between 1080p and 4k. But with 480p (or interlaced) content and above it's a necessity.

 

[Jack Of Owls]

Happy to see this topic still going. Some valuable info here, mostly thanks to The Shader Man himself, Slim Shader, The ShaderMaster General, you know him, you love him - Boom Boom Rincewind! I'm more of a plug n play type myself that just slaps a shader onto something and hopes for the best that it looks good, and not one to fiddle with settings and configs, but if I need that kind of info, looks like this is the place to get it. Coincidentally, I have been recently looking for a good DuckStation (my newest emu obsession) shader and saw that Rincewind just happened to upload a couple here. Now if I can only figure out how to inject them into Duckstation using Reshade (which I only tried for the very first time with a recent game I was testing - My Time At Sandrock - that looked incredbly, unacceptably washed out but the Rehade preset completely fixed it. I'm beginning to think that shaders and reshade can cure cancer )

No no, DuckStation has ReShade integrated *into it*, so you can use ReShade shaders *within* DuckStation! They show up in the available shader list in the Duckstation GUI if you copy it into the appropriate folder.

So I have two variants in my repo:

1. The bog standard ReShade variants

You use these with emulators like PCSX2 as you'd normally use ReShade with modern games, so as a post-processing step. This has limitations when it comes to accurate scanline and interlacing emulation (the post-processing shader has no way of knowing about the actual internal resolution of emulated image), but that's the best we can do.

https://github.com/johnnovak/CRT-Guest-ReShade/tree/main/ReShade

Also keep in mind I've only fixed the NTSC variant so far. The other two kinda work, but they have bugs. I'll do them later this year, the guy who originally converted them made some errors.


2. The Duckstation specific ReShade variants

This will give you superior result in Duckstation as the shader is aware of the native emulation resolution, can handle interlacing perfectly, and so on. *Only* use these "ReShade++" variants for DuckStation for best the results!

https://github.com/johnnovak/CRT-Guest-ReShade/tree/main/Duckstation

---

I will put all this info into the README of my repo because it might confuse some people, yeah...

My hope is the PCSX2 will also adapt the native ReShade format in the future, but we'll see.

About 4k, yeah with 240p content you won't see a night and day difference between 1080p and 4k. But with 480p (or interlaced) content and above it's a necessity.

Oh, that's good to know, that I just place them in the \shaders\reshade\Shaders folder and they show up in the GUI. Your screenshots always look like what I imagine CRT shaders should look - not obvious and intrusive, like what most ill-configured shaders I see in captures on forums look like that shader enthusiasts like to show off as ideal; ideally ugly is more like it. Thanks for the updated Duckstation shaders. As mentioned in another post, I use Lottes as a general purpose shader for all my 8 and 16 bit emus. The scanlines are still too big for my tastes (especially in mGBA) but at least not too overwhelming.

 

[Jarpie]

If so many players know about this, why do none of the endless number of indie developers build the filters on top of the pixel graphics? Why do they not draw the pixels with the filter already on?

You kinda answered this in your question: they don't have any idea about this. For example, they are younger people who grew up with LCDs.

Then people who grew up with CRTs but only had a PC and VGA monitor are also largely unaware of this as VGA monitors were tack sharp compared to TVs and home computer monitors (which were small TVs sold as monitors). Also, *all* VGA cards hardware 2x integer upscale low-res content, so for 320x200 graphics (most common in DOS games), you get 640x400. Because of this, VGA low-res graphics look blocky. There is some CRT effect, but it's subtle.

Contrast this with home computers and consoles that output 240 content on SD TVs and home computer monitors—half the vertical resolution of a VGA monitor! (or less)

But some modern games do feature built-in CRT shaders, and some of them are quite good.

There are exceptions to home computer monitors, C64 connected via S-Video or especially Amiga connected via RGB to Commodore's own 1084 is as sharp as those VGA monitors.

 

[Rincewind]

There are exceptions to home computer monitors, C64 connected via S-Video or especially Amiga connected via RGB to Commodore's own 1084 is as sharp as those VGA monitors.

No, they're not. VGA monitors have higher dot pitch and VGA cards double-scan 320x200 content to 640x400. VGA monitors can't accept 15kHz signals.

Most Commodore monitors are fixed 15kHz monitors; they're essentially small TVs. The difference between Amiga & C64 connected to an 1084 and a typical VGA monitor is huge—the 1084 smooths the "pixels" a lot more and there are visible scanlines in NTSC modes.

Well, go and read my article from the first post and check the screenshots

 

[Jarpie]

There are exceptions to home computer monitors, C64 connected via S-Video or especially Amiga connected via RGB to Commodore's own 1084 is as sharp as those VGA monitors.

No, they're not. VGA monitors have higher dot pitch and VGA cards double-scan 320x200 content to 640x400. VGA monitors can't accept 15kHz signals.

Most Commodore monitors are fixed 15kHz monitors; they're essentially small TVs. The difference between Amiga & C64 connected to an 1084 and a typical VGA monitor is huge—the 1084 smooths the "pixels" a lot more and there are visible scanlines in NTSC modes.

Well, go and read my article from the first post and check the screenshots

1084s is still one of the best of those old video monitors, better and sharper than a lot of (if not most) of the 14" tvs of the time, and they are very desired for a reason nowadays, and go for a good amount of buckaroos.

 

[Rincewind]

There are exceptions to home computer monitors, C64 connected via S-Video or especially Amiga connected via RGB to Commodore's own 1084 is as sharp as those VGA monitors.

No, they're not. VGA monitors have higher dot pitch and VGA cards double-scan 320x200 content to 640x400. VGA monitors can't accept 15kHz signals.

Most Commodore monitors are fixed 15kHz monitors; they're essentially small TVs. The difference between Amiga & C64 connected to an 1084 and a typical VGA monitor is huge—the 1084 smooths the "pixels" a lot more and there are visible scanlines in NTSC modes.

Well, go and read my article from the first post and check the screenshots

1084s is still one of the best of those old video monitors, better and sharper than a lot of (if not most) of the 14" tvs of the time, and they are very desired for a reason nowadays, and go for a good amount of buckaroos.

Yeah, they're good for sure and I liked them a lot. My shader setup emulates the 1084s. They were a big step-up for me from the small 14" Nokia TV I used with my Commodore 64. These were really very high quality small TV sets, essentially.

It's a bit crazy to buy them now for say more than 50 dollars, though—they're all on the way out and can't be repaired as the production of good quality spare parts stopped in the early 2000s. If you have one, enjoy it while it lasts, but there are lots of organic materials in these that just develop cracks and deteriorate after a few decades.

Plus these monitors were just prone to break down after a few years of use; they had a good picture but they were among the least reliable Commodore monitors, actually. It's quite surprising we still have a few in a mostly working order—well, that's survivor bias for you.

 

[Rincewind]

Related: here is some fucking joker peddling *an empty box* (!) of a Commodore 1084S for 149 AUD. I bought most of my SVGA CRTs for less than that, and even those purchases were made at inflated current prices...

I would not pay that money for the monitor itself, knowing it can break any time. People are also peddling replacement flyback transformers for it for 175 AUD... Good quality parts supply stopped in the early 2000s, so I have no idea where those are from...

Just wow. These four digits mean $$$$ for the greedy and some poor gullible guy will pull the trigger on it.

 

[Jarpie]

Rincewind What kind of shader would you use in PC games made around 1997-2002? Like Fallout, Arcanum, IE-games etc?

 

[Rincewind]

Rincewind What kind of shader would you use in PC games made around 1997-2002? Like Fallout, Arcanum, IE-games etc?

On 1080p, 2x integer scaling and that's it. It's not the SVGA CRT experience, but that's the closest on 1080p. There just aren't enough pixels to do anything better.

For 1440pThe and 4k, I recommend the shader I did for DOSBox Staging for double-scanned VGA. Check out the 640x480 SVGA examples on our front page:
https://www.dosbox-staging.org/

You can also see it in action on this 640x480 HoMM example (that's 4k):
https://www.dosbox-staging.org/static/images/front-page/heroes-of-might-and-magic.jpg

It's a tweaked variant of Hyllian's single pass CRT shader. I'm sure there are PCem and 86box ports of it so you'd only need to carry over my 4k or 1440p shader param settings.

The problems:

• You need at least 1440p for 640x480 (that's just the bare minimum at fullscreen because 640 x 3 = 1440)
• You need 4k for 800x600 and up (or for 640x480 in smaller than fullscreen)
• You'd need to apply the shaders via ReShade if running the games natively, that can be tricky. Or you can use PCem or 86box which support shaders, but they require a beefy host CPU and sound emulation can get glitchy.

So ideally we'd run these games natively on Windows on a 4k monitor and apply shaders as a post-processing step somehow. I haven't experimented much with this because I went with the real hardware and CRT route for this era.

 

[Jarpie]

Rincewind What kind of shader would you use in PC games made around 1997-2002? Like Fallout, Arcanum, IE-games etc?

On 1080p, 2x integer scaling and that's it. It's not the SVGA CRT experience, but that's the closest on 1080p. There just aren't enough pixels to do anything better.

For 1440pThe and 4k, I recommend the shader I did for DOSBox Staging for double-scanned VGA. Check out the 640x480 SVGA examples on our front page:
https://www.dosbox-staging.org/

You can also see it in action on this 640x480 HoMM example (that's 4k):
https://www.dosbox-staging.org/static/images/front-page/heroes-of-might-and-magic.jpg

It's a tweaked variant of Hyllian's single pass CRT shader. I'm sure there are PCem and 86box ports of it so you'd only need to carry over my 4k or 1440p shader param settings.

The problems:

• You need at least 1440p for 640x480 (that's just the bare minimum at fullscreen because 640 x 3 = 1440)
• You need 4k for 800x600 and up (or for 640x480 in smaller than fullscreen)
• You'd need to apply the shaders via ReShade if running the games natively, that can be tricky. Or you can use PCem or 86box which support shaders, but they require a beefy host CPU and sound emulation can get glitchy.

So ideally we'd run these games natively on Windows on a 4k monitor and apply shaders as a post-processing step somehow. I haven't experimented much with this because I went with the real hardware and CRT route for this era.

Ah gotcha, I only have 1080p :/

One thing what I miss in the games made for CRTs is that natural "dynamic depth" of what CRT monitors had, especially DOS games look so flat compared to how they looked on CRTs, but games from late 90s and early 2000s still does suffer from the lack of that to some extent. That's what I'd love to emulate using shaders.

 

[Rincewind]

One thing what I miss in the games made for CRTs is that natural "dynamic depth" of what CRT monitors had, especially DOS games look so flat compared to how they looked on CRTs, but games from late 90s and early 2000s still does suffer from the lack of that to some extent. That's what I'd love to emulate using shaders.

Yeah, me too, and sadly the shaders alone can't help with that. It's mostly due to the lack of true black levels in TN and IPS monitors. Graphics tweaked for CRTs with true blacks lose their vibrancy with raised blacks on flat panels. I did tweak my VGA shaders with the flat panel and 90s VGA monitors side by side, and yeah, it's physically impossible to achieve the same vibrant image due to the flat screens dynamic range being more compressed because of the raised blacks.

Using offset lighting help a bit with that, but the real solution is some self-emissive technology with true blacks like OLED.

Like you noted, from the early/mid-2000s onwards, games start looking OK on flat panels. That's because the artists started using flat panels with raised blacks themselves and mitigated for the lack of true blacks and the different dark gamma in the art itself.

Lol, the name "flat panel" is quite descriptive, isn't it? I've just realised this

 

[Nutmeg]

You can also see it in action on this 640x480 HoMM example (that's 4k):
https://www.dosbox-staging.org/static/images/front-page/heroes-of-might-and-magic.jpg

Gorgeous blending on the dithered areas.

 

[Jarpie]

One thing what I miss in the games made for CRTs is that natural "dynamic depth" of what CRT monitors had, especially DOS games look so flat compared to how they looked on CRTs, but games from late 90s and early 2000s still does suffer from the lack of that to some extent. That's what I'd love to emulate using shaders.

Yeah, me too, and sadly the shaders alone can't help with that. It's mostly due to the lack of true black levels in TN and IPS monitors. Graphics tweaked for CRTs with true blacks lose their vibrancy with raised blacks on flat panels. I did tweak my VGA shaders with the flat panel and 90s VGA monitors side by side, and yeah, it's physically impossible to achieve the same vibrant image due to the flat screens dynamic range being more compressed because of the raised blacks.

Using offset lighting help a bit with that, but the real solution is some self-emissive technology with true blacks like OLED.

Like you noted, from the early/mid-2000s onwards, games start looking OK on flat panels. That's because the artists started using flat panels with raised blacks themselves and mitigated for the lack of true blacks and the different dark gamma in the art itself.

Lol, the name "flat panel" is quite descriptive, isn't it? I've just realised this

I've had plasma TV from 2012 but it broke a few days ago, I've played some late 90s and early 2000s games on it, and they looked a bit more of what they should, like Baldur's Gate 2, but it still doesn't quite look the same as it did on CRT. Maybe I should just shell out some money on 17" CRT monitor, that should be good enough size for most games.

 

[Rincewind]

Maybe I should just shell out some money on 17" CRT monitor, that should be good enough size for most games.

Yeah, that's what I did. Buy a few, and don't pay too much for them; their days are numbered.

I also mourned my Panasonic plasma that died a few years ago... But my Sony OLED is quite nice too.

 

[Jarpie]

Maybe I should just shell out some money on 17" CRT monitor, that should be good enough size for most games.

Yeah, that's what I did. Buy a few, and don't pay too much for them; their days are numbered.

I also mourned my Panasonic plasma that died a few years ago... But my Sony OLED is quite nice too.

I got 4K television, and I was wondering what shader would you use for games like Baldur's Gate 2 and other games from that era to emulate the CRT look? I'm already using reshade on BG2 but not with any CRT shaders.

 

[Jrpgfan]

Coincidentally, I've been playing with a few shaders on Retroarch for the Mega Drive.

I'm brazilian and there's some guy in a br forum I participate that makes a lot of shaders for old school consoles so their games look close to how they did back then on a CRT panel.

Just now I was using his CRT Guest Advanced NTSC shader while playing Streets of Rage 2 and I quite liked the results:

note: that rainbow effect only shows up when the camera is moving. When it's static, the light just flickers(like a defective light bulb in a rundown bar). However, when I take a screenshot, it shows even with the camera static and I don't know what to do for that to not happen.

I remember that effect did exist back then with the NTSC mega on composite but I don't know if that's how it behaved or if it's 100% accurate. Still better than the bare naked game without shaders on the emulator though:

Here's a picture I took from my phone(not optimal obviously but good enough to give you an idea how the light actually looked, although the rainbow pattern shows up a little bit more on the phone picture than what I see here too, but it's closer):

I tried recording a video but it ended up being innacurate too. Looks like the creator was striving so much for fidelity that he got even the recording part right(recording CRTs with a phone doesn't work that well either).

 

[Jrpgfan]

This one simulates a Sony Wega Triniton(there's even a curvature). The image is clearer/sharper and more colorful compared to the NTSC shader but it doesn't do the dithering effects as well, which I consider very important for the Mega Drive as its games use it a lot:

And this one is another NTSC shader(CRT Hyllian NTSC Rainbow on Retroarch's repository). It's a little bit clearer/sharper than the other NTSC shader I used above and with less pronounced "rainbow effects". This one might be my favorite so far for the Mega:

 

[Rincewind]

Jrpgfan The Mega Drive was special as it has really low quality video outputs compared to pretty much anything else. It had a really blurry output, therefore the dither patterns blended in interesting ways. Based on my research (I never had a Mega Drive) the CRT Guest Advanced NTSC results seem authentic for the RF output.

For S-Video, this is a photo of an actual CRT TV in action. This is closer to the CRT Hyllian example of yours (but that's probably a bit too high-quality for the Mega Drive):

@Jarpie I've already replied to you in detail what shaders to use for Win 98 era games a few posts above.

 

[tommy heavenly6]

This one simulates a Sony Wega Triniton(there's even a curvature). The image is clearer/sharper and more colorful compared to the NTSC shader but it doesn't do the dithering effects as well, which I consider very important for the Mega Drive as its games use it a lot:

You can use blending shaders (I recommend sgenpt-mix) to blend the dithered patterns and keep the image reasonably sharp. A comparison, first image without it, second image with it:

 

[Jrpgfan]

This one simulates a Sony Wega Triniton(there's even a curvature). The image is clearer/sharper and more colorful compared to the NTSC shader but it doesn't do the dithering effects as well, which I consider very important for the Mega Drive as its games use it a lot:

You can use blending shaders (I recommend sgenpt-mix) to blend the dithered patterns and keep the image reasonably sharp. A comparison, first image without it, second image with it:

By 'blending shaders' do you mean a type of shader, or mixing that shader with others(like the Sony Wega shader I posted)?

edit. nvm figured how to do it. That dithering shader needed to be on first pass to work that's why I wasn't seeing any difference.

The picture does retain the sharpness but maybe it got a bit too sharp. Any way to change those settings inside the shader's script?

 

[tommy heavenly6]

The picture does retain the sharpness but maybe it got a bit too sharp. Any way to change those settings inside the shader's script?

Shader settings on RetroArch. The sharpness settings will depend on the kind of shader you're using, some are more customizable than others. If it doesn't have a good sharpness tuning setting, what you can do is preppend NTSC-adaptive to it and then tweak the parameters to your liking (and then preppend sgenpt-mix if needed).

 

[Jrpgfan]

Apparently the user who made that sgenpt-mix shader(Hyllian) is the same dude on the BR forums I mentioned above. Looks like he made half the shaders on Retroarch's repository.

I didn't know it was him at first because he uses a different username there.

He's been tinkering with overlay shaders now:

Spoiler

 

[Asdow]

Rincewind What kind of shader would you use in PC games made around 1997-2002? Like Fallout, Arcanum, IE-games etc?

On 1080p, 2x integer scaling and that's it. It's not the SVGA CRT experience, but that's the closest on 1080p. There just aren't enough pixels to do anything better.

For 1440pThe and 4k, I recommend the shader I did for DOSBox Staging for double-scanned VGA. Check out the 640x480 SVGA examples on our front page:
https://www.dosbox-staging.org/

You can also see it in action on this 640x480 HoMM example (that's 4k):
https://www.dosbox-staging.org/static/images/front-page/heroes-of-might-and-magic.jpg

It's a tweaked variant of Hyllian's single pass CRT shader. I'm sure there are PCem and 86box ports of it so you'd only need to carry over my 4k or 1440p shader param settings.

The problems:

• You need at least 1440p for 640x480 (that's just the bare minimum at fullscreen because 640 x 3 = 1440)
• You need 4k for 800x600 and up (or for 640x480 in smaller than fullscreen)
• You'd need to apply the shaders via ReShade if running the games natively, that can be tricky. Or you can use PCem or 86box which support shaders, but they require a beefy host CPU and sound emulation can get glitchy.

So ideally we'd run these games natively on Windows on a 4k monitor and apply shaders as a post-processing step somehow. I haven't experimented much with this because I went with the real hardware and CRT route for this era.

Any idea why these (well, vga-4k.glsl) won't work out of the box with cnc-ddraw? You can define glsl shaders to use with it when the renderer is set to opengl, and we're bundling it with JA2 1.13 to help with compatibility. I was curious to see how it would've looked with your shaders, seeing as hyllian-updated.glsl works without a hitch.

https://github.com/FunkyFr3sh/cnc-ddraw

EDIT: Slightly changing the vertex shader to simply pass TexCoord to texCoord did the trick and now it's functioning. Not sure why it doesn't like the texture coordinate scaling that's there originally.

 

[Hellraiser]

This one simulates a Sony Wega Triniton(there's even a curvature). The image is clearer/sharper and more colorful compared to the NTSC shader but it doesn't do the dithering effects as well, which I consider very important for the Mega Drive as its games use it a lot:

And this one is another NTSC shader(CRT Hyllian NTSC Rainbow on Retroarch's repository). It's a little bit clearer/sharper than the other NTSC shader I used above and with less pronounced "rainbow effects". This one might be my favorite so far for the Mega:

Here's how that same scene should roughly look like on real hardware, take it with a grain of salt since I could have fucked up camera settings (it looks better on the video I accidentally took though, maybe I should try to record one with a tripod...). This was taken using a model 1 japanese megadrive and my "flat" trinitron.

OG 30 year old SEGA composite cable with all it's faults (mono only, no red RCA jack) and those of NTSC signal, closest to what you might have had back in the day (although maybe you used the RF cable or the filters on the composite signal were worse in the TV you had, I noticed mine has fairly noise-free composite video since it's an early 2000s model), the light's dithering gets blended:

RGB cable, modern cable by RGC with all the bells and whistles (C-Sync, screening, blah blah blah). Not an actual NTSC look as RGB is after all it's own color coding signal, plus RGB cables weren't that popular worldwide so it's unlikely this is the look from your youth (does not apply to frenchmen, I think their megadrives came with RGB by default since SCART was their invention and widely adopted there ever since it was invented in the late 70s). Since the image is too sharp a dithering pattern is kind of visible on the light (in person it looked a bit similar in what to that on your first screenshot), although not as bad/as much of an eyesore as in Earthworm Jim or the Lion King had though:

I don't have s-video cables and the TV doesn't support s-video anyway (it's a budget model where they cut costs like they could, it also only has one internal speaker so no stereo sound without external speakers/headphones for instance).

I think the difference in colors is not due to camera setting but coming from the cables, it's less washed out IRL in both cases though, but there's definitely more blue in those brick walls on RGB and a noticeable difference in colors as one would expect from RGB vs composite.