Hey, thought I'd chime in here because I see a few people are seeing the same problems I saw. I'm not very far into the game yet (and have only tried KH2FM), because I was encountered some issues that were nagging me.
First, the game would have a couple frames drop every 2-3 seconds, this wasn't very noticeable when playing at the default 30 fps cap, because it would only drop to about 25-27 fps before recovering and it was such a brief drop you'd have to be REALLY looking for it. However when using the 60fps cheat code, the drop would feel like the entire game paused for about .25 seconds because the drop was so severe. By the time the fps counter refreshed to display the current fps during the drop it was reading 45, but i suspect its actually going to 0 for just a few frames, maybe even only one, and then recovering quickly after that, and it just takes longer to climb all the way back to 60 than 30.
The second, which turned out to be directly related, was entering combat, whether due to enemies or just because you swung your weapon, caused a massive fps drop that persisted until you exitted combat, even the idle combat animation triggers this spike. With no enemies around, simply walking to exit the idle animation after swinging, instantly fixes the fps. At 60fps the drop is down to 27-29, at 30fps the drop is to 20-25, although I haven't tested with many enemies around. Jumping also seemed to trigger this sometimes.
After some searching I found this thread:
https://forums.rpcs3.net/thread-197278.html
Here Zaliaa noted that the battle fps drop wasn't present in build 0.0.3-6396 (
https://ci.appveyor.com/project/rpcs3/rp.../artifacts) but WAS present in build 0.3.3-6402 (the very next build) and has persisted ever since.
Switching to 6396 also fixed these little fps "stutters" I was experiencing every few seconds as well and allowed me to play at a stable 60fps for gameplay. The thread mentions visual light shaft artifacts, and I've seen videos with it, but personally I haven't experienced it (yet) on this build. The only downsides are the 60fps somehow
feels less smooth than with the latest build when its not stuttering, when opening the oddjob menu (and I assume others) and when pausing, the background is just a black screen instead of a still of what was rendered before you entered the menu or pause screen, and the 2D faces are a little... "stuck" sometimes at 60fps, but not all the time, this isn't present in the latest build, but its still smoother than 30fps.
But its worth it to not fps drop in combat and not have those stutters. The black screen is extremely minor, and the 2D faces are minor.
The last issue I've encountered is that if you boot directly from the .self file, the game doesn't fill out the window fully, as if I needed to use the screen options from the game selection menu to expand the screen space. This issue is circumvented by booting the game normally and then selecting kh2fm and getting into the game that way, as it remembers the screen options you choose. This wasn't present in kh 1.5 even though it had the same system in terms of the screen space options. This is only annoying because I'm not able to transition from the game selection into kh2fm 100% of the time, sometimes it hangs at a black screen (making the entire emu non-responsive), and others I'd get an error message and a hard crash.
As a side: I've found Vulkan actually performs better than OGL like some others have been saying, IDK if this is because of my system vs theirs or what, but I get like double the performance out of Vulkan, while others were saying that got better results from OGL, the only issues I've run into with Vulkan is using GPU cache for upscaling crashes the game, but I never saw performance gains in this game with that option anyway. And when the game does the white fade transition after the memory cutscenes when playing as roxas between days, the game would hang. As in, after the memory cutscene ended and it faded to white to transition to the cutscene with roxas to begin each day froze the emulator. This isn't present in OGL but from what I've read, this issue doesn't persist passed Roxas, you can also skip these cutscenes and avoid the issue.
Really if the devs could figure out how to get those stutters and fps drops gone without sacrificing the other improvements the latest builds have brought, the only issue keeping this game from being perfectly playable would be the Vulkan hangs after the memory cutscenes when playing as Roxas. At least, so far. I'll post again with other issues I encounter and hopefully the workarounds as well when I've completed the game. But, from what I've heard it doesn't have world or boss specific problems like kh 1.5 did, at least not that aren't also present when ran on the console. Hopefully the xemnas fight isn't broken on the Emu like it is on the ps3
BUILD:
i7-7700k @ 4.8GHz
2x GTX 970
16GB DDR4 RAM @ 3200MHz
Settings:
CPU
recompilers
spu threads: 1
auto load libraries
no other options
GPU
vulkan
Aniso: 16x
res: 1920x1080
res scale: 300%
threshold: 1x1
no other options
Don't use GPU cache for scaling with Vulkan, SPU threads doesn't seem to do anything, additional CPU options don't seem to do anything, additional gpu options don't seem to do anything except slow the game down. If you want less screen tearing, don't bother with Vsync, driver forced or through emu (neither does anything), just play in windowed and let your Windows do it for you. OGL works fine except its slower.
So I've made it passed the Roxas part of the game and am now playing as Sora and I discovered something interesting.
But first a couple new bugs I encountered:
https://gfycat.com/RepulsiveRightFirebelliedtoad
https://i.imgur.com/phjAqIs.jpg
The first is a gif of what happens every time the screen is cutting to static due to Roxas encountering something that was not supposed to be in his data world. This same effect also happened at the "restoration" status shots during cutscenes. Luckily this bugged static has the same effect in terms of how it impacts the scene, but I thought I'd share this. I didn't look for a solution to this.
The second is an image of what's happening whenever there is Depth of Field post effects (so far only in cutscenes, including those camera shots at the beginning of boss battles like the Axel fights). Looks like the way DoF is handled in this game is they either render the object twice, or simply copy the render image for each object and then present them with a blur effect. In this case, the edges of the people are supposed to be slightly blurred, but the blurred image isn't placed behind the objects, is off to the side for some reason.
In the build I was using (0.0.3-6396) no option fixed the DoF shift problem, nothing even had an effect whatsoever, so I decided to see if it persisted in the latest build (0.0.4-7214) and it didn't! Which was nice, but not all that surprising. DoF isn't used enough for it to be worth playing the game with the constant stuttering, and the fps drops while in battle mode.
But now for the interesting part. It seems now that I'm Sora and not Roxas, neither of these issues are present anymore! I don't know why exactly, all I did was overwrite the old files with the new build after playing on the old one for the first 3 hours of the game.
However, I did notice when I was first fiddling with settings (before I realized I had to use an older build) that sometimes during the stutters, Roxas' hair spikes would blink black and then blink back in, I think his sleeves were doing this too but I can't remember. I didn't think about it's significance until later on, but I seem to remember thinking it happened at higher resolutions (I believe I was at 4k), but I've been having a lot of trouble recreating this bug, so I can't make a gif/img of it or say what the conditions exactly were.
Anyway I'm at 4k now with Sora on the latest build and there's no stutter or textures blinking on Sora and there's not even fps lag in battle, so it makes me believe Roxas is causing both problems, because even going back and playing as Roxas again, these issues reappear, and continue to be absent with Sora. I'm now at Yen Sid so the combat I've experienced is limited, but I haven't had any fps drops playing at 4k.
I've also encountered a gameplay bug related to 60fps, but I'm pretty sure this isn't due to the emulator, as its seen in all versions of kh2 played at 60fps. Sometimes, things fall faster. Actually, it's more like things don't get hit as high, and start falling
sooner but still fall at the same rate. Here's two examples, ones at 30 and the other at 60, if you compare them when the balls are at the same height, they hit the ground at the same time, they just don't get hit as high by Sora.
https://gfycat.com/AromaticFoolishBrontosaurus
https://gfycat.com/HeftyThreadbareAsiaticmouflon
Ball juggling is pretty much impossible at 60fps because you only hit the ball half as high or less, so you can't get to it to hit it again before it hits the ground, sometimes it actually falls below the finisher of your combo so you miss mid combo. I think this influences how high enemies and Sora get hit by attacks as well because it seems like at 30fps I'm always using aerial recover, but almost never at 60fps, but I'm not 100%.
I'm not really sure there's anything this emulator could do to get rid of this one though, it was patched for ps4 pro I believe (along with other 60fps and port related bugs), so maybe someone could patch this game specifically, instead of trying to patch the emulator to do something, but I'm not terribly hopeful, using hotkeys, its easy enough to switch between 30 and 60fps for now.
Lastly, a minor bug present in all builds and so far with any combination of options I've used is, sometimes, during cutscenes (or scripted parts of battles, like when fighting the large Nobody in the dream sequence) the entire screen will dim somewhat. Seems to be when there's supposed to be a brief flash of light, and it persists a short duration. It can get worse as well, the dimming seems to be able to "stack," so to speak, if the bug is encountered in quick enough succession.
TL;DR fps drops while in battle mode and stutters in current builds (0.0.4-7214) not present while playing as Sora, only present for Roxas, which makes me think theres something wrong with how Roxas is being rendered/treated by the emu. Old builds (0.0.3-6396) that don't have these issues with Roxas have bugged DoF.