"60Hz" Lighboost curiosity

[masterotaku]

It seems that I triggered some bug with 3D Vision 2 while playing Castlevania: Lords of Shadow 2. I could reproduce it 2 out of 2 times.

Steps:

1. Start playing CLOS2 with the Helixmod fix. I don't know if this is needed for this bug, but it makes the game look better in 3D. I use the high convergence fix.
2. Have Rivatuner Statistics Server showing its information on-screen.
3. Alt+Tab out of the game after pausing (I was ingame both times), book opened.
4. Go back into the game. Unpause the game.
5. Profit. RTSS info doesn't show up, but using the show and hide keys will toggle the effect I'm about to tell you.

The game is now playing at 30fps per eye with some sort of black frame insertion. It flickers, but there's no judder or motion blur. If you disable 3D Vision, the glasses keep flickering but aren't necessary anymore. The game will be running at 60fps with Lighboost with no motion blur. The fps can't be monitored, but it's obvious because disabling RTSS makes it switch INSTANTLY to 120fps.

It's a curious trick that only works for this game (unless someone finds another), but it shows how good Lightboost + black frame insertion can be. Alt tabbing out and using other games doesn't trigger this effect in those games, unfortunately (and RTSS works in them).

If someone else has this game and 3D Vision 2 glasses, feel free to try it .

Edit: By the way, as the game runs at constant 60fps per eye for me, I couldn't check if there is a GPU usage drop when I enabled this trick. I'll see what I can do.

Edit 2: tried it with RTSS hidden before alt tabbing. Now it's running at 30fps in 2D (no motion blur, lots of flickering), and a flicker madness in 3D (I guess 15fps). This is how I want to play 30fps games :p.

Edit 3: lol, it crashed when I tried to restore from checkpoint. Yes, this is a bug XD.

[Trip]

For those skyrim fans out there I found a rather curious setting in the more recent enb versions (shader injector). Which is called skipnumber of frames. When I enable this setting in correspondence with vsync at 120hz. It has this weird rolling scan effect. The game says it is running at 120 fps according to fraps. So whatever this setting says it does it is not skipping a frame but it seems like it is (from what I can see) injecting a black frame. My monitor is one of the older generation of 120hz monitors (lg w2363d) and it could very well be that this rolling scan effect I see is just the afterimage of the black frames. If you turn up the setting to 2 the weird scan-effect is gone although the game feels really sluggy (probably input latency) but it looks very smooth.
I suspect that like aforementioned the shader is injecting a black frame for every frame it skips. So when set to 1 the game runs at effectively 60 fps. When set to 2 the game runs at 40 fps. If anyone with a strobe backlight monitor would like to give this a go put your monitor at 120hz enable vsync in both the nvidia controll panel and the enbseries ini (otherwise it will crash for some reason for me). And put skipnumberofframes to 1. If I am correct skyrim should now have black frame insertion and its game engine will run at 60 fps(which means no physics bugs).
I thought this was a good time to post it since this is a rather similar story and I didnt know it was worthy of a new topic.
I know this for some time and have tested this on both my old system i7-920 + ati 5870 + windows 7 64 bit and my new system i5-4670k + gtx 780 + windows 8.1 64 bit. I dont know the exactly what enb versions have this setting as I have done a clean up of skyrim since it kept crashing from all the mods. But it should be in the most recent one.

Edit:
The exact name of the variable is VSyncSkipNumFrames and was added in enb version 243 link below states it
http://www.enbdev.com/mod_tesskyrim_v0245.htm
It can be found in enblocal.ini not in enbseries.ini hope it didnt confuse anyone

[masterotaku]

Nice finding! I tried it at 120Hz and it worked sometimes, but it desynchronized frequently and it's annoying to have a huge black bar every few seconds. At 90Hz it was more stable, and at 60Hz my eyes almost died with the light of day . Loading times were very long at 60Hz. Weird :S. Now I'm going to sleep.

[Trip]

Nice finding! I tried it at 120Hz and it worked sometimes, but it desynchronized frequently and it's annoying to have a huge black bar every few seconds. At 90Hz it was more stable, and at 60Hz my eyes almost died with the light of day . Loading times were very long at 60Hz. Weird :S. Now I'm going to sleep.

I think the desynchronization is just the fps dropping below 60 fps which is not uncommon with skyrim + enb and a ton of mods . The black bar you see is just what is usual vsync behavior it will show the previous frame again (the black frame) so if you see that frame long enough you will see a black bar.I dont know how it looks on your screen though as I have yet to test out strobing backlights. The 60hz long load times thing I can understand because skyrim at sub 32 fps I believe will have longer loading times (yup great engine bethesda...). Imagine if nvidia or amd would just have this setting in there control panels. Locked 60fps games (not uncommon) could still look better on 120hz displays.

[Falkentyne]

How are you supposed to download this thing?
Clicking the "zip" file link on that page you linked, redirects to yet ANOTHER page: http://enbdev.com/ with no download anywhere.

Ok you linked the .245 version when the current one is .264.
Anyway I got it 'working' but the gamma is like MASSIVELY Washed out and totally unplayable like this....It does work if antialiasing is disabled but the gamma......my god......how do I fix that?

[masterotaku]

Anyway I got it 'working' but the gamma is like MASSIVELY Washed out and totally unplayable like this....It does work if antialiasing is disabled but the gamma......my god......how do I fix that?

If you didn't download a preset, it uses a default configuration, meaning that you should configure contrast, gamma, colors, etc yourself. If you want the game to look like the normal game, this is the line you need:

UseOriginalPostProcessing=true

I'm not at home, but I know that there's another line like that just below. Put that to true again.

Source: http://enbdev.com/doc_skyrim_effect_en.htm


About those fps drops with the black frame insertion, I can't monitor fps with RTSS if that effect is enabled. Is the game trying to render 120fps and then discarding half of that? I'm asking because I usually have constant 60fps indoors (and a great part of the time outdoors), and I had fps drops there (120Hz). At 90Hz, real fps should be 45fps, but outdoors it dropped too many times, I think.

[Trip]

About those fps drops with the black frame insertion, I can't monitor fps with RTSS if that effect is enabled. Is the game trying to render 120fps and then discarding half of that? I'm asking because I usually have constant 60fps indoors (and a great part of the time outdoors), and I had fps drops there (120Hz). At 90Hz, real fps should be 45fps, but outdoors it dropped too many times, I think.

I reinstalled enb today and a fresh skyrim and it runs pretty much solid at "120 fps" which in reality means 60 fps with VSyncSkipNumFrames=1. I can monitor my fps with fraps and btw if you press alt enter when enb is enabled you can see your actual fps. So it will show 60 fps while fraps says 120 fps. If I get my hands on a strobed monitor I will certainly try this setting out another time to see how it looks like then.

[masterotaku]

OK, adaptive vsync was the culprit. Now it works correctly with normal vsync . For me, it drops to 40fps very frequently. It's much harder to get 60fps with this black frame insertion at 120Hz than without it at 60Hz.

Advantages:

- Overdrive artifacts disappear completely (the same happens in Retroarch).
- Zero motion blur experience at any fps (it inserts black frames as needed).

Disadvantages:

- Less fps in general (in my experience).
- Flickering can be very annoying at 40fps, and a lot more at 30fps. Variation in fps is what makes it bad.

This is similar to what we would get with G-Sync + ULMB if it were possible, but with bigger steps in fps (depends on Hz).

PS: lol, I'm derailing my own thread, even if the topic is a bit similar .

[Chief Blur Buster]

60Hz LightBoost is emulatable via software-based black frame insertion.
This feature is found in a few emulators already, such as MAME and WinUAE:
http://www.blurbusters.com/mame

Someone needs to write a resident utility that can do software-based black frame insertion for all games (at least in full screen windowed mode), by flashing an opaque black window 60 cycles a second, causing the whole screen to flicker. Or some kind of a graphics driver hook (much like FRAPS is). Then we'd be able to do 60Hz strobe with any 120Hz strobed monitor.

[Trip]

Disadvantages:

- Less fps in general (in my experience).

I have a small theory as to why that happens if it is incorrect just say so I dont want to give any misinformation. The black frame insertion method that he uses most likely never happens at the gpu driver level. But it is more like a drawcall send from the cpu to gpu. So what happens is the gpu "renders" this drawcall. And it will just sit there waiting in the buffer to get scanned out for 8.33ms @ 120hz. In this time no other frame can be rendered since the backbuffer is filled with this black frame. The game engine can prepare the drawcall but it cant render it on the gpu. If you have a normal 60hz/60fps situation every frame will get way more render time since if the drawcall is ready it can start rendering.

So with blackframe insertion the time the gpu has to render the frame for the next vsync will be:
16.667 - 8.33(black frame) or 16.667 - drawcall time(if it takes more then 8.33ms) = render time

Whereas with no blackframe insertion the gpu will have this much time:
16.667 - drawcall time = render time

If this could be done at the driver lvl you could just send out a black frame when the vblank is happening and there has already been sent a normal frame. By filing the front buffer with this black frame and not flipping the two buffers. I dont know if any enthusiast is capable of doing this sort of stuff though or if nvidia/amd would want to implement it. What would also be a solution without any additional lag would be a three frame buffer on the gpu so the black frame can just sit there and the last one can render at its own pace but this would be a waste of vram since storing a black frame in precious vram isnt exactly helpfull.