Kronos very poor compatibility and peformance

Libretro Cores
#41

It seems there are several issues with the saves :

  • while they are saved into the srm files, it doesn’t seem they are loaded when you restart the game, save implementation might be wrong in the libretro port (it works in standalone version though)
  • the ÿ is indeed weird, seems like they are “FF” (hexadecimal) inserted between each characters, the content might be close/identical to mednafen’s if we manage to remove them.

Edit : actually, i think Kronos save format might be the same as ssf save format

Kronos & Beetle: Sega Saturn Saves
#42

Today I tried Kronos and was a little bit surprised about the issues. I also had lags and some strange rendering issues. Moreover I thought Kronos can filter textures in a bilinear manner.

#43

kronos used to be interesting in that it offerd perspective correction. A few years ago this feature got broken so there is no reason to use this core IMO.

#44

@papermanzero hard to say what was your issue without knowing anything about your setup and the games you ran, in the first place Kronos is not glitchless, no emulator is afaik.

@GemaH well, don’t stay with the default perspective correction setting, maybe ? you can use gpu/cpu tesselation as workarounds for the wobbling issue if your gpu/cpu are good enough, and the new opengl CS renderer is an accurate VDP1 renderer (it renders quads line per line, same as original hardware, using compute shaders) which totally deprecates this setting if you got a sufficiently powerful gpu. Anyway, even if i didn’t communicate about it, hearing that there is no reason to use this core because a specific feature XXX is missing, while the core actually has the best version of this feature XXX, which required around a year of work, is rather unfair.

1 Like
#45

Any setting i tried didn’t give me results nearly as good as when i first tried the emulator. I remember being very impressed as i had never seen Saturn games look this way. But after an update or two, i could never achieve the same good result. And i didnt backup the core back then so i cant post some screens.

Anyway Its been a couple of months since i last tested this so ill give it a try to see if something changed. I admit i was harsh though, i only use Mednafen since my system can handle it and the rock solid graphics of Kronos was the only thing thay made me use it. So apologies if i was unfair.

#46

No problem, my bad too for not writing a progress report for a long time. If you got a powerful gpu, the “OpenGL CS” video renderer is highly recommended. The old OpenGL renderer is mainly kept for performance & compatibility reasons.

#47

@GemaH btw, i finally wrote a progress report

2 Likes
#48

You should be more specific. This sort of complaints adds nothing. What game were you running? What are those strange rendering issues?

Kronos is great, and can make 3D Saturn games look fantastic.

#49

I tried this updated version today. I still can’t find any combination of options that will make the polygons stable without the “wobbling” effect the Saturn and Playstation had.

I know it’s the accurate behavior but i specifically remember an older version of Kronos having the option to remove the wobbling and make everything look rock solid. It looked amazing but it’s not working anymore and i don’t know if i’m doing something wrong. I tried OpenGL CL with perspective correction or tessalation and i don’t see any differences.

1 Like
#50

@GemaH when you say it’s currently wobbling and it wasn’t in the past, do you mean it was better than this ? Or do you have a different result ?

I don’t remember it being any better in the past :thinking:, and tbh i’m not sure it’s technically possible to furthermore improve this without implementing something to replace textures with HD versions. At the very least i don’t think the current level of “wobbling” in Kronos is any worse than Mednafen’s.

Edit : it seems i’m being trolled by retroarch’s audio sync when recording :thinking:

#51

Ok, i’ll try to explain myself better because my point wasn’t clear.

The “wobbling” effect is normal. Saturn has it. All emulators have it. It’s not better or worse in Mednafen. It looks the same across all Saturn emulators. That’s the normal behavior. You can clearly see it in the video you posted as well. Look at the environments and objects as the camera pans left or right. You can see a “wave” effect, i can’t explain it better. But again, this isn’t an issue because that’s how the real Saturn operates.

Now, the same applies to Playstation. This console (the real one) also has a similar issue where the polygons aren’t exactly stable. And it’s actually even worse here. The only console at the time that had stable/steady polygons was the N64 because the real console could do perspective correction. You can read about it here:

Now recently, there was a new thing in some Playstation emulators (called PGXP i think) that would fix this and make the 3D graphics look solid, without this wobble effect the real Playstation had. Beetle PSX HW has that option. It makes the 3D graphics look better than the real Playstation in more ways than just a resolution bump.

Now, what i’m trying to say is that Kronos also had this OPTION at some point. The first time i ever tried the core, it was the one feature that made it stand out for me. It made the polygons rock-solid, just like PGXP. I think i only had to enable perspective correction and i was set. I mean “perspective correction” should be the option that fixes this because that’s what perspective correction does on the real N64.

But after an update, the effect stopped working and never came back. I did post about it back then but i don’t remember getting an answer. And i also never backed up the “working” core. I always backup but for some reason i didn’t with Kronos. So i can’t even demonstrate this. And i don’t know if you tried to demonstrate the effect in the video you posted but if you did, it clearly doesn’t work for you either.

Oh and one last thing. I see Sega Rally being shown for this version but this particular game doesn’t even work for me in Kronos for some reason.

#52

Ok, so you are talking about a PGXP-like option to fix original hardware issues, well, such a thing (requires Z, which doesn’t exist on saturn) has never been implemented in Kronos, and at no point i can remember perspective correction giving better results than gpu/cpu tesselation. It might have been a weird fluke if you really saw rock solid polygons, do you remember around which time it was ?

#53

It was around the time Kronos was introduced as a libretro core.

#54

There is a weird emulation issue with Sega Rally USA where the video output is shut down and never opened again, every other version/region of the game (including the superior version Sega Rally Plus Netlink Edition USA) works properly.

#55

Regarding the perspective correction, what does the option do then? I see no difference between that and the other options like tessellation. The game looks like regular Saturn games no matter what.

Are you the developer of this core if i understand correctly? Then, dude, if what i saw was a fluke, it means you accidentally made a PGXP like implementation on accident. Is this possible? Because i don’t know, the graphics were too perfect for me to think it was a fluke or bug. I thought it was an intentional thing and “perspective correction” as a name made sense for the effect to work. Because what else it does then?

Now i need to find some older version of the core. Because i think i’m going Jack Nicholson in The Shinning crazy here.

#56

I wrote the libretro port, maintain it, and i’m also a regular contributor upstream, especially on the arcade front. Sadly i don’t know much about 3D programming, only some basics, but afaik a PGXP-like feature would require a Z (while N64 got it natively, PSX is calculating and storing it in a buffer if i understand correctly), which is something we don’t have, so i don’t see how having rock solid polygons could happen without it being some kind of weird fluke.

Polygon mode (perspective correction, cpu & gpu tesselation) is ignored if you enable the OpenGL CS renderer, because it’s actually just a workaround for the inherent warped textures issues from rendering VDP1 with OpenGL. Tbh i’m surprised at the lack of differences between perspective correction and tesselation, just last week perspective correction would give me textures like this :

Having same results for cpu & gpu tesselation is normal, it’s just about reducing charge on either the cpu or the gpu

#57

I realize I am late to the topic but I just want to throw my vote in to include chd support. It’s not the amount of compression that is important… although it is nice that it is very similar to zip. The problem with zip is the load times when launched through an FE/Rocketlauncher since it has to de-compress first. The chd is usable instantly just like an iso.

#58

You are late indeed, it was added last year.

1 Like
#59

LMAO, ok ty :slight_smile:

#60

I specifically remember loading Daytona USA around the first time i tried the core myself and being impressed by the stable graphics and lack of wobbling polygons. And then being disappointed the effect wasn’t there in later versions. I know sometimes our brains play tricks on us and we remember things wrong but this isn’t a childhood memory from 20 years ago. It’s very specific. Yet, i can’t even find a single Youtube video to prove it. So yeah, i think my brain is busted then, there’s no other logical explanation.

Anyway, here’s me and you talking about it about a year ago:

First reply even suggests wobbling fix was indeed a thing? Maybe someone else also saw the same thing?