SGENPT-MIX - Sega Genesis Pseudo Transparency Mixer shader

[Hyllian]

I think it’s time to release something I was working. For now on I’ll release only in slang. I’ll only release in other languages if someone really need it.

Version 5 released: sgenpt-mix (slang)

Whatsnew:

• Figured out how to soft the blending level so that some artifacts can be mitigated through a new param;
• New param called BLEND_LEVEL so that the blend level can be modulated.

At level 1.0, it blends the same way as before. At level 0.0 it blends the minimum. Minimum is different from doing nothing. On reality, on minimum level it’ll blend very soft dithering, like a very high pass filtering. I think that at level 0.0 the Genesis games look great even if they don’t have any dithering. Look at the comparison screens below:

sgenpt-mix OFF:

sgenpt-mix ON with Blend Level at 0.0:

[Hyllian]

I was testing some Genesis games with Blend Level at 0.0 and they look really great. It works as a very soft smart low pass filter.

Try Adventures of Batman and Robin and see the cloud at the first chapter. What’s more interesting, you can see the cloud dithering paused (still), but can’t see it when in movement. if you turn off sgenpt-mix, the dithering can be seen in movement.

With this, the genesis games looks like snes games. The excess of dithering is mitigated without creating visible artifacts. I love the results of Blend Level 0.0.

[HyperspaceMadness]

@Hyllian

I love the results of Blend Level 0.0.

I’d have to agree! This is really looking great!

[Hyllian]

Now Mortal Kombat II is playable on genesis. Looks like the snes version.

[Red-gehog]

Hello everyone! I’m here to thank Hyllian for this shader, as I was combing through various topics on antidithers and other ways to simulate composite blending, and I came across this incredible shader!

This new addition is like a fade, it is much more like the TV mix, only very clear and so, in my opinion, it avoids some false positives in a more accurate way.

Tested on the Sonic 3D Blast DX 2017, It was wonderful! Thanks!

[Red-gehog]

It removed as much dither as possible without ruining the small texts like the “Sega 1996” in the title, and preserved the letter M in the game menu. With mdapt and gdapt the sonic shadows were left with undetected pieces of dither, as I had to decrease the detection to save the texts, now with this shader, they are perfect as they were on TV!

I’m almost sure that I’ll be able to make just one preset for my entire Sega Genssis library!

[Hyllian]

That’s nice! Which Blend Level are you using? On most genesis games a BL=0.0 is enough because they only have low contrast checkerboard dithering. OTOH, some games exhibit high contrast dithering that only disappear or get minimized using a bigger BL= 0.8 ~ 1.0.

[Red-gehog]

I’m using it at 0.50 or 0.70, today when I get home from work I will test some more to see how much I need.

This was a screen that bothered me a lot! But now it’s fine with me, the dither looks like on my old TV!

[Hyllian]

KKK the dithering made the filtering nuts. Genesis artists used and abused dithering for effects. The new TVs didn’t help genesis games. It looks so much better with a good filtering!

[Red-gehog]

Really, especially the Eternal Champions

[Red-gehog]

I had a lot of difficulty filtering this screen, there was no way to adjust the vertical lines in mdapt without causing failures, and with gdapt it’s the same. Mdapt and gdapt are still an excellent option for me, but not in a case like this in Great Circus Mystery.

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Examples:

gdapt with max error prevention lvl and max of color metric exp

mdapt with color metrix exp in 10.00, vl lo 9.95 & vl hi 10.00

sgenptmix with bl 50

[Hyllian]

Good. Different approaches to the same issues. I’m sure there are other examples where mdapt/gdapt exhibit advantages. Dithering isn’t an easy issue to solve. There are too many particular cases where some approach is better than others. In this case, it’s clear that SgenPT-mix does a more homogeneous treatment of the picture, even if it degrades more overall.

[HyperspaceMadness]

@Hyllian

There are too many particular cases where some approach is better than others. In this case, it’s clear that SgenPT-mix does a more homogeneous treatment of the picture, even if it degrades more overall.

Yeah, I think it does a nice job to holistically adjust the image. In the latest version of the Mega Bezel I’ve got both SgenPT-mix and Mdapt, with SgenPT-mix after MDAPT so one or the other or both can be used together

[Hyllian]

That’s a great addition!

[Red-gehog]

It is a great idea to use mdapt with sgenptmix. But on my presets I usually use bilateral or slow-bilateral, the mdapt checkerboard is perfect, but the transparencies are too blurred with these blur filters or denoisers. I have a preset with jinc2dedither to filter checkerboards, sgenptmix for the vertical lines and right after the bilateral, so all the transparencies are very sharp.

[Red-gehog]

I even wanted to know, is it possible to insert an option to activate checkerboads while using the blend?

[Hyllian]

Not now. I’ll look if it’s possible to only filter pseudo transparencies next time I do my tests. It needs many tests to see if it bring any harms to what is already working.

[jayjayjay]

Obrigado pelo trabalho fantástico com shader para dither!

A versão 5.0 ficou incrível, seria possível uma versão em gsls para que eu possa utilizar no Raspberry Pi 3 com Retropie?

Desde já agradeço!

[Hyllian]

Yes, I’ll convert to glsl soon.

[Hyllian]

Here you go:

sgenpt-mix-v5 (glsl version as requested)