CRT luminofor fading simulation
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Re: CRT luminofor fading simulation
Googling for "CRT phosphor emulation" and I've found this video:
Emulation of CRT Phosphor + Curved Screen + Fade
But I can't test this GPU shader on my old gma4500
Can anyone test this filter on Stars - Field demo (PD).nes?
Emulation of CRT Phosphor + Curved Screen + Fade
But I can't test this GPU shader on my old gma4500
Can anyone test this filter on Stars - Field demo (PD).nes?
Re: CRT luminofor fading simulation
Do you have some Csound program which can emulate luminofor fading for a single pixel? If it is treated as an audio signal, I wonder what it will sound like?
(Free Hero Mesh - FOSS puzzle game engine)
Re: CRT luminofor fading simulation
CRT phosphors emit light as either a first or overdamped second order exponential decay¹ after the incoming electron beam radiation has stopped. There will be some complication for the electron beam size, such that a "single" phosphor may actually be struck multiple times in quick succession as the screen is redrawn. Vectorscopes have a different retrace pattern, but are subject to the same caveats.
¹ 'Properties of Fast-Decay CRT Phosphors' by Pfahnl, ftp.helpedia.com
¹ 'Properties of Fast-Decay CRT Phosphors' by Pfahnl, ftp.helpedia.com
Re: CRT luminofor fading simulation
What do you think?
- Attachments
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- demo02.png (18.71 KiB) Viewed 6921 times
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- demo01.png (15.38 KiB) Viewed 6921 times
Re: CRT luminofor fading simulation
Looks like motion blur instead of light trails...
Re: CRT luminofor fading simulation
Yes.Looks like motion blur instead of light trails...
On the my first video you can see that white stars have greenish phosphoric tails.
This effect is similar to "afterglow" but no blur.
I need to make more quality video.
When you see live on real CRT traces looks much longer, brighter and phosphoric.
Re: CRT luminofor fading simulation
I see. At anyway, even for a single pixel, it's brighter and "bigger" due to his properties in a CRT monitor.
Re: CRT luminofor fading simulation
Yes... this will be pretty hard so simulate in emulators.Zepper wrote:At anyway, even for a single pixel, it's brighter and "bigger" due to his properties in a CRT monitor.
Re: CRT luminofor fading simulation
Having done a very simple simulation assuming a half-life of 33ms, without any of the electron beam simulations, the effect is fairly subtle:
(This is a still from the loop that bisqwit made to demonstrate animmerger. Any obvious errors are from it.)
This is just "current displayed frame" = maximum("previous displayed frame" * .7,"current notional frame")(This is a still from the loop that bisqwit made to demonstrate animmerger. Any obvious errors are from it.)
Re: CRT luminofor fading simulation
I'm shifting right (div by 2) the previous RGB pixel to simulate an exponential decay. Then, I'm adding the new pixel. Well, I see it produced a similar effect from the previous screenshot...
- HardWareMan
- Posts: 209
- Joined: Mon Jan 01, 2007 11:12 am
Re: CRT luminofor fading simulation
You're missing a few points:
1. If the new point brighter than the old one - the new one is drawn just as they are.
2. If the new point darker than the old one - then the strength of the effect will depend on the difference in brightness of the old and the new point. Therefore, the maximum effect will be viewed as a new point - black.
3. Each one has a different color phosphor decay rate. I have already given a link to a video showing it. First fades blue phosphor, then green and red kept the longest. Therefore, it is necessary to work on the sub-pixels separately.
1. If the new point brighter than the old one - the new one is drawn just as they are.
2. If the new point darker than the old one - then the strength of the effect will depend on the difference in brightness of the old and the new point. Therefore, the maximum effect will be viewed as a new point - black.
3. Each one has a different color phosphor decay rate. I have already given a link to a video showing it. First fades blue phosphor, then green and red kept the longest. Therefore, it is necessary to work on the sub-pixels separately.
Re: CRT luminofor fading simulation
It looks to me like the half life depicted in that recording is on the order of 100µs for blue, 300µs for green, and 2ms for red. With modern phosphors with those halflives, there will be no visible interframe blurring from the phosphors, only from your eyes.HardWareMan wrote:3. Each one has a different color phosphor decay rate. I have already given a link to a video showing it. First fades blue phosphor, then green and red kept the longest. Therefore, it is necessary to work on the sub-pixels separately.
Re: CRT luminofor fading simulation
So, it's not a matter of interpolating frames or blending pixels at every X ms.
Should I say "outputting pixels whiter than white"?
Funny things ^_^;;
Should I say "outputting pixels whiter than white"?
Funny things ^_^;;
- mikejmoffitt
- Posts: 1353
- Joined: Sun May 27, 2012 8:43 pm
Re: CRT luminofor fading simulation
This looks nasty, but it's closer than the other approximations above, which are more like motion blur.Zepper wrote:So, it's not a matter of interpolating frames or blending pixels at every X ms.
Should I say "outputting pixels whiter than white"?
Funny things ^_^;;
Most of what makes the fading phosphor look look like it does is phosphors not going dark instantly.
This looks more like an LCD response time emulator, ironically, from the video.Eugene.S wrote:Googling for "CRT phosphor emulation" and I've found this video:
Emulation of CRT Phosphor + Curved Screen + Fade
But I can't test this GPU shader on my old gma4500
Can anyone test this filter on Stars - Field demo (PD).nes?
Re: CRT luminofor fading simulation
Oh, mein gott
It's the LSD emulator with psilocybine mushrooms!
I want to see it on motion
Last edited by Eugene.S on Wed Jun 19, 2013 3:28 pm, edited 1 time in total.