Stereoscopic 3D quirks

[ThreeDeeJay]

I recently found out that NVIDIA 3D Vision (shutter 3D glasses kit) still supports OpenGL quad buffer even on consumer GPUs (up to RTX 2080 Ti since it requires driver <=425.31 which newer GPUs don't support) in fullscreen mode, so I figured I'd give ioquake3 a shot and after some tinkering I was pleasantly surprised that it does indeed work, so you can probably remove "untested" from the readme.

I added the full instructions here but basically we need opengl1 since I think newer/ES doesn't support quad buffer 3D. So I just had to run this command:

ioquake3.x86_64.exe +set cl_renderer opengl1 +set r_stereoEnabled 1 +set r_zProj 200 +set r_stereoSeparation 25

Now I noticed a few quirks:

• Some UI gets cut off, like the player's head.
• The weapon looks massive. I'm guessing it's using that one trick to render the weapon in a separate pass that has higher draw priority so that it never clips through walls, but that messes up the stereoscopy (it looks huge and looks deeper than the ground even though it's drawn on top of it, which looks confusing). Maybe it should be shrunken down so it's proper scale, while still keeping draw priority.
• Some text (like You fragged X) is only rendered for one eye.
• Left and right views aren't synchronized. I know shutter 3D technically shows one view after the other, one at a time, but I think it should still be possible to e.g. render the left view, freeze time, then render the right view even though it might effectively add visual delay.
  - This wiki article mentioned some sort of dynamic depth crosshair, but for me it's still static, fixed at screen depth, and I'm not sure if it was ever implemented.

[ThreeDeeJay]

Weirdly enough, World of Padman 1.7 does have a working dynamic depth crosshair. 🤔

Also, I was able to use MESA GLon12 to translate OpenGL into Direct3D 12 which 3D Vision can stereoize (flattened UI, weapon render at the right depth and with synced eyes, even), but it's also limited to up to 425.31/2080 Ti.
https://airtable.com/appByPZJsOQSVGDID/shrAfMuGs1IOIEpRT?uMgeK=recEsQegev48KEuRz

*You can see the 3D effect if you cross your eyes to merge the thumbnails then focus.

[NuclearMonster]

The crosshair is likely not effected because our qvms aren't being loaded.

https://ioquake3.org/help/players-guide/#sharedlibraries

To force ioquake3 to use shared
libraries instead of qvms run it 
with the following parameters: 
+set sv_pure 0 +set vm_cgame 0 
+set vm_game 0 +set vm_ui 0

[ThreeDeeJay]

Awesome, that indeed fixed it! 👍
It reversed the eye views but luckily there's a flag in the NVIDIA driver profiles to swap them so I updated the guide.
Any clues about the other quirks?

[NuclearMonster]

I'm sorry. Can't help with the other quirks. This is not a path we test for or have anyone working on at the moment.

[ThreeDeeJay]

Fair enough.👌
I'll leave it open in case there's ever some interest in fixing them since they're technically visual bugs of a built-in feature.
And I know quad buffer is quite niche, but I'd imagine Anaglyph 3D mode (which is way more common) might be affected too.

That said, I wouldn't mind if this was closed, since GLon12 addresses all the other issues, though it requires running without quad buffer which makes the crosshair's depth static again. I guess I'll have to look into disabling the game's crosshair and enable 3D Vision's.

I also wonder if it's possible to move the HUD elements to the top edge (or allow the gun to render on top of it) so that I can increase popout so the weapon looks like it's outside the screen without the HUD causing a visual conflict since it's always drawn at screen depth.

[ThreeDeeJay]

By the way @NuclearMonster is there a way to get the launch parameters to stick after a game restart?
Because right now I'm launching with this:
ioquake3.x86_64.exe +set cl_renderer opengl1 +set r_stereoEnabled 1 +set r_zProj 200 +set r_stereoSeparation 25 +set r_mode -1 +set r_customWidth 1920 +set r_customHeight 1080 +set com_maxfps 333 +set r_swapInterval 1 +set r_colorbits 32 +set r_texturebits 32 +set r_ext_texture_filter_anisotropic 1 +set r_ext_max_anisotropy 16 +set r_detailTextures 1 +set r_picmip 0 +set r_simpleMipmaps 0 +set sv_pure 0 +set vm_cgame 0 +set vm_game 0 +set vm_ui 0
and the next time I launch without any parameters, the crosshair is back to being at a fixed depth even though all the other stuff was remembered 🤔

I just want to make it as simple as possible for the guide, and I can't add all the parameters to a desktop shortcut's target because it's too long and gets cut off.

[NuclearMonster]

the issue is usually that when you connect to a multiplayer server that has sv_pure enabled, it will override the shared libraries we distribute and unload them. This is the way quake 3 is meant to work, but it is also why we rarely make fixes for the game code (what is in the shared libraries/qvms).

[ThreeDeeJay]

It gets disabled even if I'm just playing offline with bots, unless I manually launch the game with the parameters above, but I just figured out that I can just add this to %APPDATA%\Quake3\baseq3\q3config.cfg:

seta sv_pure "0"

I'm more interested in the offline mode for now, but you mean there's no way to make the dynamic crosshair part of the default/safe/pure settings without needing sv_pure "0" so it still works in protected servers?

btw is there a way to enable the dynamic crosshair without r_stereoEnabled 1?
That way we could still use it with GLon12 instead of the native 3D mode.