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I grew up coding demo effects on the C64 and the Amiga. I always loved how the vblank synced ultra-smooth graphics slide over the screen while the CRT had a so

by Flow 7y ago

I grew up coding demo effects on the C64 and the Amiga. I always loved how the vblank synced ultra-smooth graphics slide over the screen while the CRT had a sort of magical "glow" to the picture. I sit here by a nice iMac but often feel like that magical glow just isn't there even though the picture is 1000 times better than my old television I used. Is there some kind of effect that can be applied to achieve this glow on a good LCD screen? Or maybe it's just the lying of the nostalgia of childhood memories?

byuu 7y ago
Phosphor glow is one of my favorite effects. One of these days I'd really love to have a software-mode C++ filter for that. It can be done through filtering, but it's really hard to make it look good. A person named Psiga made this mock-up for Secret of Mana in Photoshop that has always astounded me: https://sites.google.com/site/psigamp3/PhosphorSimTest1.jpg https://sites.google.com/site/psigamp3/PhosphorSimTest1.jpg Unfortunately, no one's been able to figure out exactly how it was made to replicate it in software. But something like it would really add a lot. There are however really good CRT simulation pixel shaders, such as CRT-Royale: http://emulation.gametechwiki.com/index.php/CRT-Royale http://emulation.gametechwiki.com/index.php/CRT-Royale
- Fr0styMatt88 7y ago
  That phosphor image looks great! I wonder if it could be used to train a style transfer neural network to create a filter to replicate it?
  - nitrogen 7y ago
    Since the physics are known it's probably going to be easier to simulate from first principles.
    - vanderZwan 7y ago
      You could probably use machine learning for fine-tuning the parameters of whatever fast approximation comes out of that though. (having a plausible first-principles model and then automatically tuning the knobs until the error with a ground truth is minimised is a form of machine learning, right?)
- crankylinuxuser 7y ago
  That's Seiken Densetsu 3 (unreleased in US but fan translated by Neill Corlett) :)
  - sb057 7y ago
    It was actually officially released internationally a few months ago as Trials of Mana!
    - Deimorz 7y ago
      It's not out yet, the release date is April 24, 2020.
      - sb057 7y ago
        You're thinking of the remake; the 16-bit original was recently released as part of a trilogy bundle.
- Ibethewalrus 7y ago
  The Mana looks like two filters, a scan line plus a blur one. Lmk if you’d like me to give it a go to replicate in Photoshop
  - byuu 7y ago
    I would like that, thank you! A few people have tried over the years, and we even contacted the person who made the original image, but he didn't remember how he did it ^-^;
- vanderZwan 7y ago
  > Unfortunately, no one's been able to figure out exactly how it was made to replicate it in software. Could that be due to something like the phosphor glow having non-linear properties or something?
  - DiabloD3 7y ago
    Look at CRT draw in slow motion. You have an ultra bright flash, then an alarmingly quick phosphor glow falloff. You'd need, basically, a high hz HDR monitor with an actual sub-ms response time... so you can superbright blink the character, essentially black framing it. The rest of the actual softness of the glow can be emulated conventionally with shaders (there are some super swanky terminals and emulators that have that part already done).
    - Vel0cityX 7y ago
      > there are some super swanky terminals and emulators that have that part already done Like 'cool-retro-term': https://github.com/Swordfish90/cool-retro-term https://github.com/Swordfish90/cool-retro-term
    - vanderZwan 7y ago
      Although this flicker would indeed be necessary for a 100% accurate reproduction, I'm not sure that is really the thing that current CRT shaders are missing for feeling "just right". After all, the linked example image feels very convincing and yet is static.
- ZeikJT 7y ago
  Psiga seems to be a person named Patrick Murphy (based on the recent change history: https://sites.google.com/site/psigamp3/system/app/pages/recentChanges https://sites.google.com/site/psigamp3/system/app/pages/rece...) and they've uploaded at least one other phosphor test such as this one from 2011: https://sites.google.com/site/psigamp3/phosphorsim-gettingclosermaybe.jpg https://sites.google.com/site/psigamp3/phosphorsim-gettingcl... They also uploaded something as recently as 2017 so it might be possible to reach out to them and get a response? Not sure if that helps find / reach out to them but I can hope.
  - byuu 7y ago
    We have pinged them in the past about it, actually ^^;; It's been a mini-obsession of mine since I found it, hahah. They regrettably don't remember how it was made.
    - ZeikJT 7y ago
      Ah bummer. I would have thought they'd have kept the PSD lying around somewhere like I do and it would've shed some light. Maybe someday someone will figure out something that looks right!
- jbay808 7y ago
  Pretty sure a cross correlation of the source and resulting image will reveal most of the transformation's recipe, aside from a few details like the fine grid lines added in. If I have time tomorrow I might take a crack at it.
nineteen999 7y ago
Agreed, love this kind of look. I emulated a curved screen, phosphor glow and scan lines somewhat in my Unreal Engine based Z80 emulators, although I think the look could still be improved further. This is fairly easy to do with UE4 shaders and geometry for the curved screen, a bit harder to do all from scratch though in a standalone program I would think. https://i.imgur.com/rIY1he8.png https://i.imgur.com/rIY1he8.png

by Flow 7y ago

byuu 7y ago

Phosphor glow is one of my favorite effects. One of these days I'd really love to have a software-mode C++ filter for that. It can be done through filtering, but it's really hard to make it look good. A person named Psiga made this mock-up for Secret of Mana in Photoshop that has always astounded me: https://sites.google.com/site/psigamp3/PhosphorSimTest1.jpg https://sites.google.com/site/psigamp3/PhosphorSimTest1.jpg Unfortunately, no one's been able to figure out exactly how it was made to replicate it in software. But something like it would really add a lot. There are however really good CRT simulation pixel shaders, such as CRT-Royale: http://emulation.gametechwiki.com/index.php/CRT-Royale http://emulation.gametechwiki.com/index.php/CRT-Royale

Fr0styMatt88 7y ago
That phosphor image looks great! I wonder if it could be used to train a style transfer neural network to create a filter to replicate it?
- nitrogen 7y ago
  Since the physics are known it's probably going to be easier to simulate from first principles.
  - vanderZwan 7y ago
    You could probably use machine learning for fine-tuning the parameters of whatever fast approximation comes out of that though. (having a plausible first-principles model and then automatically tuning the knobs until the error with a ground truth is minimised is a form of machine learning, right?)
crankylinuxuser 7y ago
That's Seiken Densetsu 3 (unreleased in US but fan translated by Neill Corlett) :)
- sb057 7y ago
  It was actually officially released internationally a few months ago as Trials of Mana!
  - Deimorz 7y ago
    It's not out yet, the release date is April 24, 2020.
    - sb057 7y ago
      You're thinking of the remake; the 16-bit original was recently released as part of a trilogy bundle.
Ibethewalrus 7y ago
The Mana looks like two filters, a scan line plus a blur one. Lmk if you’d like me to give it a go to replicate in Photoshop
- byuu 7y ago
  I would like that, thank you! A few people have tried over the years, and we even contacted the person who made the original image, but he didn't remember how he did it ^-^;
vanderZwan 7y ago
> Unfortunately, no one's been able to figure out exactly how it was made to replicate it in software. Could that be due to something like the phosphor glow having non-linear properties or something?
- DiabloD3 7y ago
  Look at CRT draw in slow motion. You have an ultra bright flash, then an alarmingly quick phosphor glow falloff. You'd need, basically, a high hz HDR monitor with an actual sub-ms response time... so you can superbright blink the character, essentially black framing it. The rest of the actual softness of the glow can be emulated conventionally with shaders (there are some super swanky terminals and emulators that have that part already done).
  - Vel0cityX 7y ago
    > there are some super swanky terminals and emulators that have that part already done Like 'cool-retro-term': https://github.com/Swordfish90/cool-retro-term https://github.com/Swordfish90/cool-retro-term
  - vanderZwan 7y ago
    Although this flicker would indeed be necessary for a 100% accurate reproduction, I'm not sure that is really the thing that current CRT shaders are missing for feeling "just right". After all, the linked example image feels very convincing and yet is static.
ZeikJT 7y ago
Psiga seems to be a person named Patrick Murphy (based on the recent change history: https://sites.google.com/site/psigamp3/system/app/pages/recentChanges https://sites.google.com/site/psigamp3/system/app/pages/rece...) and they've uploaded at least one other phosphor test such as this one from 2011: https://sites.google.com/site/psigamp3/phosphorsim-gettingclosermaybe.jpg https://sites.google.com/site/psigamp3/phosphorsim-gettingcl... They also uploaded something as recently as 2017 so it might be possible to reach out to them and get a response? Not sure if that helps find / reach out to them but I can hope.
- byuu 7y ago
  We have pinged them in the past about it, actually ^^;; It's been a mini-obsession of mine since I found it, hahah. They regrettably don't remember how it was made.
  - ZeikJT 7y ago
    Ah bummer. I would have thought they'd have kept the PSD lying around somewhere like I do and it would've shed some light. Maybe someday someone will figure out something that looks right!
jbay808 7y ago
Pretty sure a cross correlation of the source and resulting image will reveal most of the transformation's recipe, aside from a few details like the fine grid lines added in. If I have time tomorrow I might take a crack at it.

nineteen999 7y ago

Agreed, love this kind of look. I emulated a curved screen, phosphor glow and scan lines somewhat in my Unreal Engine based Z80 emulators, although I think the look could still be improved further. This is fairly easy to do with UE4 shaders and geometry for the curved screen, a bit harder to do all from scratch though in a standalone program I would think. https://i.imgur.com/rIY1he8.png https://i.imgur.com/rIY1he8.png