New CRT shader from Guest + CRT Guest Advanced updates

sonkun · 12 January 2025 14:36

That shouldn’t change anything I hope. I don’t plan to change any settings at all.

@guest.r So the first game I tested was that random Mega Drive racing game I posted up last time and it seems that the issue has been fixed with the checkerboard dithering looking weird and half blended on the purple and light green car:

Both cars look to be fully blended now I think. Gotta do more testing though as I don’t know if those few random red areas on the edges of the purple car along with those few darker blue/purple areas are suppose to be there or not.

Here’s with rainbows activated:

I remember @ProfessorBraun noticing something with vertical line dithering and the waterfall effect, can’t remember exactly what it was but it was mentioned some posts up. Maybe he’ll come around and do some testing as well.

guest.r · 12 January 2025 20:27

New Release Version (2025-01-12-r1):

Notable changes:

Old: new functionality added with NTSC shaders to better preserve ‘edge’ colors.
Old: fine-tuning of the new functionality for some specific cases.
New: more fine tuning, should fix/mitigate some situations.
Note: is best used with low taps number or/and color bleeding reduction.
New: some refinement on the effect, originally the sampling was point-like, producing very cut transitions (Sonic waterfall mountains…), now it’s more like sharper-linear.
Edit: small update

Download link:

https://mega.nz/file/JgRAFbLQ#oI-xGgA7XhwkOySPs2BQE5thZY3ImPcX3GgWHai41Ec

Current state of the ‘feature’:

OFF:

ON:

sonkun · 13 January 2025 04:53

Late to the party and this newer update but right away let’s get into some testing. @guest.r I think I remember what the professor was talking about with the waterfall effect, first here’s vanilla guest-ntsc:

Then here’s with the edges color setting on 10:

Is that how it’s suppose to look with all those small red areas on his body appearing like it’s “coming through” the waterfall like that? At first I tried it with my presets and thought that was happening because of all the different settings I was using but that even happens here on the vanilla shader as well.

guest.r · 13 January 2025 12:25

I wouldn’t mind these situations too much. If pixels exsist as a part of the original graphics, then it’s quite possible they are detected by the edge detecting algorithm and they become “the original color”. The heuristics involved aren’t too complicated, but i like the results in general.

RetroGames4K · 13 January 2025 15:09

Your last update looks sharper, I love the way it looks. Thanks for the great Job you are doing!!!

Jobima · 13 January 2025 16:10

Hi

is “Gamma correct” in “BRIGHTNESS SETTINGS” has bug? see the artefacts/artifacts below

I need it since it help make the image closer to https://x.com/CRTpixels/status/1497359045203738628

guest.r · 13 January 2025 16:16

No, it’s not a bug of the Gamma Correct setting, just some NTSC artifacts are becoming visible. It’s funny you picked this up too, i had allready some cleanup code ready at a point, but wasn’t released. If you lower the number of NTSC Taps, this should be greatly mitigated or go away anyway.

Jobima · 13 January 2025 16:21

here with CRT Guest Advanced without any ntsc

it seems has some problems with bit depth

guest.r · 13 January 2025 16:27

Gamma Correct just makes very dark graphics more visible, that should be it. If you want some cleanup, then just disable afterglow and lower the Black Level parameter by some points.

Jobima · 13 January 2025 16:33

I don’t want to disable them, maybe it’s better to move “Gamma Correct” function to the top of shader chain (like afterglow settings or color tweaks)?

guest.r · 13 January 2025 16:45

Prior application would affect scanline dynamics and i don’t want to do this. Post-application would be even worse. If you have issues with this, you can also increase mask boost and lower mask gamma. In general, i’m not changing these parts of code, not planned. Maybe some ‘garbage’ cleaning in core ntsc shaders and this would be it.

Cyber · 13 January 2025 18:42

You can’t just turn up the knobs too 11 and call it a day with these things. Remember these things just edit the image or rather turn up the gain but the brightness we see requires nits to be generated by the display. You can’t just edit in more nits. So if you push any setting too far, you’ll get side effects. They might manifest in clipping of colours, highlights, oversaturation, loss of dark details e.t.c.

What I’m trying to say here is that if you want to produce an image that is bright and accurate compared to a real CRT then you need to have a display that can produce enough brightness to match a CRT’s brightness even after all of the masking, scanlines and other brightness reducing CRT effects are added to the picture.

So do some research on @Nesguy’s and @MajorPainTheCactus’s work in this regard and you’ll begin to understand that you can’t always use software to solve what is essentially a hardware issue and expect to get similar results.

Sometimes we just have to learn to deal with the limitations and try our best to master and extract the most out of the software tools that we have available to us.

sonkun · 13 January 2025 23:49

Ah well ok then. Besides that everything else seems to look as good as it’s always been, both checkerboard and vertical line dithering still looks good while sharpened:

I guess I can go ahead and swap your previous update out for this new one.

guest.r · 15 January 2025 18:02

New Release Version (2025-01-15-r1):

Notable changes:

Old: new functionality added with NTSC shaders to better preserve ‘edge’ colors.
Old: fine-tuning of the new functionality for some specific cases.
Old: more fine tuning, should fix/mitigate some situations.
Note: is best used with low taps number or/and color bleeding reduction.
Old: some refinement on the effect, originally the sampling was point-like, producing very cut transitions (Sonic waterfall mountains…), now it’s more like sharper-linear.
New: improved logic of the effect. Isn’t perfect, but should do better ‘blending’.
New: Now NTSC Preserve ‘Edge’ Colors only works with 2-phase mode, the main reason is other modes don’t produce the 2-phase color smear in the same way, effects also removes all ‘desired’ artifacting. Small bugfix included.

Download link:

https://mega.nz/file/8shEUKja#7dtWeHcvGrkvHykN2QjlxFXmrFRNRU80ZlEPwjc_liA

sonkun · 15 January 2025 22:43

You’re a monster, definitely wasn’t expecting this update. Ok so right away I went and tested the Shinobi III waterfall and it looks better than before, those red areas no longer look like they’re “coming through” the waterfall anymore.

This is with the edge setting on 10:

Looks pretty damn good to me. Hopefully when the professor reappears he sees this new amazing development.

guest.r I just have one request, pleeeease enable the edge setting for 3phase again as well, it may not be useful for taking care of smearing like it does for 2phase but it indeed helps on pixel edges. Here’s an example.

First here’s without the edge color setting. Look all around Mario himself, from the back of his cap, his upper arms even the edge of his nose:

All those outer areas seem to have the pixels “faded” out.

But with the edge color setting on:

All those areas look more “filled in” now. That’s one of the main reasons I love that setting so much please don’t take that away from 3phase lol.

Jobima · 15 January 2025 23:24

maybe it’s better to separate them like chroma scaling

sonkun · 15 January 2025 23:27

Who knows. I just know I need that for 3phase it helped in making the colors pop more on those edges. Every thing else looks good.

Superdonkeyjack · 16 January 2025 00:37

Can I use these new updates with Pants sonkun mods?

sonkun · 16 January 2025 01:35

Seems to be working, just tried it out.

guest.r · 16 January 2025 16:43

Bad news is, it’s looking like another parameter has to be tweaked. But the option to have edge colors preserved with 3-phase will be probably included in next release.