Kronos very poor compatibility and peformance

Libretro Cores
#61

At some point, the wobbling was way worse because we were trying to workaround inherent VDP1 opengl emulation issues (namely, things like the holes on sega rally), it was around that time that it was decided to write a new renderer instead and to stop trying to fix the issues inherited from YabaSanshiro’s renderer. Tbh it was a bit crazy how bad it looked, especially on perspective correction, and it was also around that time i started being careful about upstream status before bumping the libretro fork.

Also, finally found some differences in F1 challenge, especially on the benetton logo, check those images :

perspective correction :

tesselation :

I’ve to say, it isn’t as bad as it was until recently, so since perspective correction is more cpu friendly, maybe it should go back to being the default setting.

2 Likes
#62

You can see the difference on the brick wall at the top left as well.

Thing is, it does fix the textures but not the polygons as they still wobble when the camera moves.

Man, if i could only find a 1.4.0 or 1.5.0 version of the libretro core. At least i would be able to confirm that i was wrong all along :sweat_smile:

#63

I’ll check older versions when i’ve some time, but after discussing about it with the author, there is little hope tbh :

  • the wobbling in sega rally is due to development decisions, they had to convert a model 2 game to lower hardware, the game is natively buggy for performance reasons (the dots on the road’s border is one such bug, and there are tons of them), Maybe some Kronos bugs at the time of 1.4/1.5 was miraculously hidding some of those issues, but it would clearly be a fluke (that’s something i really intend to look into though).
  • it appears a pgxp-like feature for saturn is simply impossible (at the very least, with the same approach), wobbling on psx was due to triangle rendering and lack of precision, pgxp fix this by calculating its own precision. That’s not how it works at all for saturn, here the rendering is pre-calculated by devs, everything from texture to quad’s deformation.
1 Like
#64

I think “OpenGL CS” only works with glcore, wasn’t written in the blog post. If anyone wants to test an old build here’s one from mid March 2019.

2 Likes
#65

Yes, Kronos uses glcore, since back in 2018, whatever the renderer, and it seems RA isn’t implementing the switch to “glcore” when current setting is “gl”, which is causing issues with several cores, i wrote an issue about it some time ago : https://github.com/libretro/RetroArch/issues/10486

#66

But with older builds the image was rendered, with latest build it renders black (audio plays) unless I explicitly change to glcore. This might be an openGL CS only thing.

#67

This is an interesting story haha

Hey @GemaH, I keep old cores in case problems arise, and also for savestate compatibility. I might have what you are looking for. Please give me an approximate date.

1 Like
#68

Yes, i remember kronos rendering unglitched image with “gl” video driver, however it was slower than the “glcore” video driver by a 5-10% margin anyway so keeping the gl video driver with kronos was a bad idea nonetheless. RA should just switch to glcore when a core is requesting glcore, it would only make sense.

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#69

Hi, Just a small question : does Kronos support .m3u files ? I know there’s not a lot a multi-discs games but it’s always convenient to have a single file to launch (especially now that RA save and load the latest used disc).

#70

No, that’s something i’ve yet to implement, iirc the few saturn multi-discs games don’t require it to be playable though.

1 Like
#71

It was sometime in 2018 or early 2019 i think. Around the time the core was introduced. Version 1.5.0 or older. Probably older.

#72

Sorry for not responding. But I did a fresh set up of retroarch. I wanted to post some screens and videos to show the issues. First, my system is a i7 4790 and a nvidia GTX 760 with win10.

I tried Nights… the redump version. The title screen is completely scrambled on the right side. Moreover with OpenGL CS and OpenGL 4.5 setting the game slows down extremely. I increased the resolution to 1080p. Even the graphics look pixelated.

I also tried House of the Dead with the same experience.

I can make some screens and videos.

#73

I just registered on the forums to ask about rendering issues I was having with Kronos, but switching to glcore was the fix. Thanks so much for bringing this up this issue.

After updating Retroarch to the latest, my video driver was set to “gl”. Using this driver with Chronos and OpenGL resulted in flickering video output. Switching to OpenGL CS resulted in a black screen, though the game was running, though the video frame could be seen when paused on the the retorarch menu.

#74

I was testing yesterday and I subscribe what you said. Nights has performance issues. I didn’t notice before because I use CHD compressed images and those have issues with NTSC (check the issue tracker), so I’m forced to use PAL what means less frames to render = better performance = greater frame time deviation ; D

#75

@papermanzero @Dogway i’ve none of those issues, as you can see this game is running pretty well on my pretty old setup (i7-2600k + GTX960) :

I can push the game to 1080p if i give up on OpenGL CS.

The version i used was redump’s “NiGHTS into Dreams… (USA, Brazil)” but there might be issues with another version ? (excluding demos, there are 8 versions of this game in redump…).

House of The Dead is also running fine at 1080p with OpenGL and 480p with OpenGL CS.

#76

I tried to reproduce the issue. However I converted my bin/cue’s to CHD which is not supported by Kronos. So I cannot support. :frowning:

#77

@papermanzero it’s getting weirder and weirder, Kronos has supported CHD for almost a year… tbh, with all those unreproducible issues, i’m starting to wonder if you are even using kronos (and not a version from 1 year ago…).

#78

Really strange :flushed: I will try a fresh set up. Every other core is working like a charm but Kronos is somehow difficult :joy:

#79

I tried now both. Neither chd or cue is working.

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Edit: Ok I found the issue in retroarch :roll_eyes: Will report the issues I have tomorrow with several games.

#80

@papermanzero looking forward to your report