I did not want to post this in my Vk3DVision thread as it is not related to Vulkan, but rather to OpenGL, and since Nvidia Forums are now a mess... I decided to make a new thread for this game If you don't already know, I have made a full Stereo3D fix for Wolfenstein II: The New Colossus, which you can find here: http://3dsurroundgaming.com/Vk3DVisionGames.html#wolf2. You can also check the video on Youtube (if you click on the image on my website it should take it directly there).
So, after playing Wolf II in 3D, I decided to try it the first part in the series: Wolfenstein: The New Order.
(This game originally came out in 2014 and unlike Wolf 2, it uses IDTech5 - and the notorious 60FPS cap).
So, I re-downloaded the game and booted up my "ancient" fix from 2016... It still works, but... Coming from the experience of Wolf 2, Doom Eternal, etc to Wolf 1 rendering at 30 FPS out-of-sync and those 15FPS Movies was a pretty game-breaker
Now, even in this state, I finished the game a long time ago: 0-100% complete according to Steam Achievements, so it is serviceable, but not a great experience.
The fix was also made on version 6.12 of the OGL3DVision wrapper and not the latest one.
Thus:
0. I decided to use ID5Tweaker to make the game render at 60 FPS in 3D!
This tool/hack appeared a few years after Wolfenstein New Order/Old Blood were released.
The problem with IDTech5, unlike IDTech6 - that powers Doom, Doom Eternal, Wolf 2, etc - is that in IDTech5 you would get a max of 60 FPS. The whole reason is because the GAME Time and speed of animation and game logic is directly TIED to the FRAMERATE.
At 120FPS basically the game would run at DOUBLE speed. This was the stupidest decision they ever made with IDTech5 and as we see with IDTech6 they completely changed it, where the game can now run at 1000 FPS but the game time and logic updates at 60 FPS!
ID5Tweaker unlocks the FPS and makes the game time also update at 120FPS instead of locked 60FPS. There are still issues even with the tool, but I will not go over them here.
So now, that we have 60 FPS in 3D - aka 120FPS in 2D:
I. I decided to update the fix from 6.12 to 10.1
This meant basically redoing the fix as I changed parts of the code and how I hash the shaders from 6.12 to 10.1. This more or less means redoing the fix
Once that was done, I noticed other issues that I haven't fixed before, so I had to fix those issues as well:
- Lights & Volumetric Lights
- Shadows
- Lots of decal types
- Reflections, but not Screen Space Reflections! I didn't even looked for them. Maybe I will in the future.
- Glass Reflection and Refractions
- UI at Depth & Crosshair at different Depth.
- Etc, Etc, Etc.
II. Custom Weapons Depth
Like Wolf 2, the game world is in a correct linear depth space. However, this means that if I want the world to look a bit more 3D, I need to pump a higher convergence value. This will apply a very big separation to hands & guns - since they are literally next to the camera and "not at depth". So, like before, I had to separate the Hands, Guns, Particles etc that are related to the weapons or player from the rest of the world and apply a different Stereo Depth.
III. Properly in sync Stereo 3D 30FPS cinematics!
The game uses A LOT of cinematics! Sometimes longer one between levels, but also a lot of short ones in-levels. Moving from a 60FPS 3D experience to 15FPS out-of-sync experience for 10-15 seconds felt like a "truck hit me in the face" feeling.
As a result, I have developed a new technique that will perfectly synchronize ANY video, at ANY Framerate for rendering in Stereo3D using sequential frames. Currently this is experimental in OGL3DVision but I plan to port it to Vk3DVision as well and this should be GENERIC to all games
(Currently I only target Bink Player, but I am sure the same can be done for other players).
IV. No Shaking & Accurate Blood & other Decals
If you remember the original fix, you will remember this one
The problem is quite simple to explain. The Stereo correction needs to happen in the Fragment/Pixel Shader. But this shader only have access to the inverse of the Model-View-Projection (MVP) matrix.
The correction needs to happen in Screen Space (so in MVP space).
Mike_ar69 helped me at at time to fix it and the approach was to compute the MVP from the Inverse-MVP by well.. inversing the matrix, applying the correction and then multiplying again with the Inverse-MVP to get it back in the original space.
However, when you make a Mat4 from 4 vec4's in GLSL then applying the inverse() function, you lose quite some precision. The result was technically correct, but some of that original accuracy was lost.
ALSO
Computing a matrix INVERSE in the Fragment shader (this means for every pixel on the screen) can lead to some huge computational times! Remember you don't have 1 pixel shader for a frame with this correction but 4-5-6-10 shaders! (I will let you do the math for 1920x1080p with 10 shaders doing this correction, how many matrix inverse operations will happen 
)This is the correct Mathematical approach! But, in Real-Time Computer Graphics most of the times we don't apply the direct formulas, because we do get to know some other properties of these matrices and how space computation works.
As such I looked into fixing these effects without all the extra compute required: matrix inverse (which if you know from math is not a simple operation), 2x matrix multiplications and the regular stereo3D formula.
The result is I needed just 1 operation that can be applied directly using the Inverse-MVP and the correct Inversed Depth.
Result, fully accurate Stereo3D effects with no shimmering or shacking! (As seen in the video).
V. Input Synchronization for Mouse Movement
Synchronizing the game to re-draw the same frame twice (by making the game think no time has passed between L & R frames) can be done in various ways. Remember the game engine doesn't know it is rendering Stereo (same image from 2 perspectives). It still thinks is rendering consecutive frames and as such time passes between each frame.
The approach I use in Vk3DVision is to basically Assembly edit the game engine only to advance the "game time" after the Right Eye Frame is drawn and in time for Left Eye Frame.
For INPUT I have to do the same as it changes your perception in the game world and it is not tied to the game-world-time directly.
This again can be done from Assembly, but now I have prototyped a new mechanism that SYNCHRONIZES Mouse input between frames automatically! Currently this is experimental in OGL3DVision but I plan to port it to Vk3DVision as well and this should be GENERIC to all games
as well.(I did not look at Keyboard input, nor XBOX controller input yet
)Lastly VI. Dominant Eye Rendering
I know I have talked about this feature for a long time now, but I realised I never properly showed it
In the below image: Dominant Eye is LEFT. Aiming and closing the Right RL eye will give you a perfect Aiming ability - EXACTLY LIKE YOU DO in REAL LIFE.
This image is EXACTLY as you would see a GUN in Real Life if you look down the Iron Sight with 2 eyes instead of the one
YOUTUBE Video of one of the later missions
This is a full run of the full mission (40-ish minutes long).===============================================================================================
https://www.youtube.com/watch?v=omY8oqy-40w
(And if you watched the video and liked, at least leave a "Like" on Youtube
Thanks)===============================================================================================
Please let me know in the comments bellow what is your take on all of this.
Unlike the Vulkan games, I cannot do proper Frame Synchronization here, due to how IDTech5 works - explained above - but I did try to synchronize all the components and part of the game that I could, namely video playback and input:) (I know keyboard is still pending)
Please WATCH the video in 3D and let me know, IN THE STATE showed in the video, would you play Wolfenstein: The New Order with this with new Stereo3D Fix?
Cheers,
Helifax
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UPDATE: 15/04/2021 on Wolfentein: The Old Blood
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All the features and improvements from the fix for Wolfenstein: The New Order ARE USED for the Wolfenstein: The Old Blood fix 
- Stereo3D rendering... OBVIOUSLY
- Custom Weapon Depth
- Dominant Eye - for aiming
- 30 FPS video cutscenes perfectly synchronized and in stereo3D.
- Mouse Input synchronization.
- All the Stereo3D fixes and improvements (like NO MORE SHAKING DECALS ^_^)
- etc, etc, etc...
Like before, here are a few screenshots, from the video below
YOUTUBE Video of one of the later missions called "Escape". (from Castle Wolfenstein, if you played the game before ^_^).
===============================================================================================
https://youtu.be/2Guwwu-JJpI
(And if you watched the video and liked, at least leave a "Like" on Youtube
Thanks)===============================================================================================
Hope you like it
Cheers Helifax
or wait for New Order fix and then go Wolf 2 
^^
