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Some shaders look different than in RetroArch

Open Nightskyy1 opened this issue 8 months ago • 8 comments

I would like to use crt-hyllian-3d and crt-guest-advanced-hd. These shaders are made to use with a higher internal resolution for 3D games. I tried these shaders in RetroArch at 4x internal resolution with GameCube and PS2. After that I tried the same with ShaderGlass. But it looked different with ShaderGlass. I adjusted the shader parameters in both cases to 4x internal resolution. With ShaderGlass it didn't look very good, so I think there is an issue with these shaders.

Nightskyy1 avatar Mar 15 '25 08:03 Nightskyy1

Hm they look pretty equal to me in an image test so it's probably something to do with scaling. SG doesn't have an option to upscale source (pixel size option only downscales) so for something like crt-hyllian-3d you'll need to have your source window show the game at 4x scale for example, set pixel size to 1 in SG (=no downscaling) and 4 internal resolution as shader param. Doom looks pretty good that way. A lot of shaders have been written with RA cores' specifics in mind and don't work as easily in SG, tweaking is often required (contrary to RA, SG knows nothing about your input).

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mausimus avatar Mar 15 '25 09:03 mausimus

I've added #136 to add source upscaling to SG to make this easier to accomplish.

mausimus avatar Mar 15 '25 09:03 mausimus

Thanks for the help. Here are two screenshots with crt-hyllian-3d. One is with RetroArch and one with ShaderGlass. It's PS2 with 4x resolution (1440p monitor). I made sure that the shader parameters are also set to 4x internal resolution. I also set ShaderGlass to 1x pixel size. The text looks slightly worse with ShaderGlass.

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Nightskyy1 avatar Mar 15 '25 09:03 Nightskyy1

The first one is RetroArch, the second one is ShaderGlass.

Nightskyy1 avatar Mar 15 '25 09:03 Nightskyy1

There's fewer scanlines on SG version; are you sure you need to scale x4, not x3 (isn't PS2 480 vertical)?

mausimus avatar Mar 15 '25 10:03 mausimus

That's what I would've thought too. But Dolphin and PCSX2 recommend 4x for 1440p. Here is a screenshot from PCSX2.

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Nightskyy1 avatar Mar 15 '25 10:03 Nightskyy1

Not sure what PCSX2 is doing there, I haven't used it myself. Try 3x, if it doesn't help, maybe I'll install it someday.

mausimus avatar Mar 15 '25 10:03 mausimus

This is ShaderGlass with crt-hyllian-3d. The internal resolution of the game is 3x. The shader parameters are set to 3x also. The pixel size is 1x. There are no visible scanlines and the picture looks worse. So I think 4x is correct for 1440p. Unfortunately ShaderGlass looks slightly worse with this shader than RetroArch with 4x, especially text.

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Nightskyy1 avatar Mar 15 '25 10:03 Nightskyy1