Greetings @guest.r, hope all is well. Any chance we might be able to get a mask pattern that looks like this when the phosphors aren’t energized?
You can more or less already achieve that using either negative values for the Glow parameter (shown below), or Magic Glow:
Though I have to say it’s not perfect. It seems to light up the surrounding “inactive” phosphors using roughly the same colors as the bright pixels that are causing the glow, so for example, the black area around Little Mac’s portrait is slightly tinted green since that’s what the color of his background’s portrait is, and it seems to me it should have a much more neutral tint.
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I thought about this but didn’t think the dynamics were the same. Was just wondering if we could’ve gotten a dedicated implementation since it does seem like a real part of the CRT emulation experience that we might be missing out on.
Good attempt though!
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Can also be achieved by raising the black level a little bit. Obviously not ideal.
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Maybe not but I think it is realistic. I’m pretty sure the lighting conditions would have to be right to see the physical mask, and that would lower contrast.
e.g. the black level in the three shots above looks pretty high.
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Seeing that we’re already close to achieving that look using the glow/magic glow effect. Maybe it might not be so difficult to implement the full effect in future shader revisions?
I think stuff like this is important to assist in things like the “natural” anti-aliasing and superior blending of pixels and edges that are characteristic of CRTs without resorting to simple blurs to ease the high contrast transitions, which usually tend to soften the image or contributes to a lack of focus.
What it appears like to me is that it could be functioning as a type of physical dithering pattern.
I’ve noticed that the same image with darker scanlines can look sharper but also less pixelated than the same image without scanlines or with lighter scanlines.
It’s possible that these vertical lines can have a similar effect on the image. Maybe that’s part of the “magic” that Magic Glow adds to the image as a side effect?
I’m not so concerned about Black Levels because as @Nesguy always said CRTs didn’t have perfect black levels although they were close enough to perfect.
I think the effect fails using Magic Glow because the luminance tapers from a high level to a low level, while what we would need for this effect would be an extremely low but static luminance level across the board. Only where the phosphors are lit is where the luminance would be higher than this level.
So in essence I think we can achieve this by simply having some “background” luminance applied to the Mask even when the phosphors are inactive. So instead of the Mask/Phosphors going all the way down to 0 (Off, black), Maybe they should go down to 2 or 1 or 0.2?
We could probably call it Magic Black Level or Mask Black Level? I’m sure @guest.r could come up with a better name if he so chooses to implement this.
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Oh Wow @guest.r! This is brilliant! I think @HyperspaceMadness might also appreciate this very much since it’s something that he had pointed out that he noticed for a while. Thanks a mil for taking things even closer to the real thing!
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Hi, I am kinda new to retroarch. Not a newb to emulation tho. I am wondering, where do I place the update? I have Sonkun’s shaders installed and working properly but uncertain about where I need to place the presets. Sorry for such a simple question
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I know it’s early days still but instead of this:
I’m seeing this:
So there’s a black halo?(shadow?) around the glowing phosphors. I think this might negate some of the blending properties of the effect even though you’ll still get to see the barely visible mask.
For the proper effect the phosphor must glow and blend on top of the energized mask with no black separation between the transition by default unless it is artificially added in case one would want more sharpness.
I think if you nail this, you might even be able to get away with less blur on the emulated phosphors themselves while still having smoother edges than what might have been possible before so the net effect might be a sharper, clearer image due to lower phosphor blur but smoother edges due to edges gradually fading into the inactive phosphor colour instead of a sharp black drop-off.
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One question: should this new effect be uniform all around the screen, or should it be stronger near actually illuminated phosphors? I would think it’d be the latter, and judging from pictures from the CRT thread in this forum, it would seem to bear out, but I can’t really say without an actual CRT in front of me, and even then I suspect other factors may come into play depending on the CRT and how it’s calibrated. And how would it play with the existing Glow and Halation parameters?
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I think this is your answer right here:
It’s the unenergized phosphors that can be “passively” visible so there’s no energy being applied to those to create any excitement of the phosphors and thus difference in light output. So of course it’s going to be uniform.
This is what Magic Glow already does brilliantly.
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Into the crt folder in the shaders_slang main folder. You don’t copy the base folder in the zip, but the folder’s content and you are good to go.
Yeah, i noticed it also, i guess this looks better:
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Place the sonkun folder right into the shaders_slang folder and you should be good to go. Welcome to the forum by the way. If you have any other questions you can send to my thread as well right here:
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We both replied to him at the same time lol.
Also @guest.r while I’m at and since it seems you’re working on another update I have to bring this up again. If it’s possible can you try to make it to where I can place the new upgraded grade shader into my presets where I usually always have it placed? I know you said that the after glow pass wouldn’t affect anything and that I could just place grade above it, I tried that and it indeed works that way but I really don’t want to see two different types of color managing shaders in my presets.
I think it’s a issue with the LUT or something when I try to replace the “pre-shaders-afterglow” pass with grade, not exactly sure. If it’s not possible I’ll just leave this topic alone going forward.
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New Release Version (2023-07-13-r1):
Notable changes:
- Base (black) Mask strength feature added
Download link:
https://mega.nz/file/p1p2yS7Z#4caaGaPofPLjyJhjuFslEAE7C4oqhONTqz6nYQ-VOzg
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I think i’ll need some extra time to update the new grade version like the older one was adapted. I guess it’s best to put it on my schedule.
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Definitely, looks better. Great job!
This one and the next image appear to have a very slight black separation and possibly a very slight black outline between the inactive mask and the boundary of the phosphor glow but it could just be me.
It’s not visible at all to me in these red transitions though.
This shows the combination of Magic Glow and the new Base (Black) Mask Strength feature quite well.
The area to the left of the green character (in the original image) seems to display some afterglow.
Thanks a lot @guest.r! I’m looking forward to tweaking and playing around with this new setting!
Before this, one of the ways to get this type of effect albeit improperly was to increase the gamma so that areas which would normally be dark now show visible mask the downside of this would have been washing out the mask on the brighter end. Now we can have nicer edge transitions and fades/blends to near black without suffering this penalty.
I want to see the effect this has on previously very sharp, harsh presets.
Thanks again for your hard work and dedication to the community!
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No problem at all. I’m just glad you’ll consider adding it in that way at a certain point. I wasn’t planning to do another update until I get that new grade in but in the mean time I’ll see what this new update is about that you just posted. Thank you for always making this shader better.
Hmm, there seems to be an issue with how this new feature interacts with Magic Glow around the edges of pixels. To best illustrate the problem, here’s the Base Mask strength parameter set to maximum, with Magic Glow enabled and set to its default value of 0.08:
Here’s the same, but using regular Glow:
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