NV3D-Glass

Capture a side-by-side stereo source (game, video player, Katanga producer) and re-present it as true frame-sequential NVIDIA 3D Vision output via NV3DLib. No DLL injection into the captured app; runs as a standalone .exe with an ImGui control panel.

Requirements

Install

Download the latest pre-release from the Releases page, unzip, and run NV3D-Glass.exe. The binary is self-contained - no installer.

Quick start

  1. Launch NV3D-Glass.exe. The control panel opens.
  2. Capture Source - pick Window, choose the SbS-producing app from the dropdown. Or pick Monitor to capture a whole display, or Katanga to receive from a Geo-11/Katanga producer over the shared-memory channel.
  3. 3D Vision Output - leave (auto) to let NV3DLib pick the 3D-Vision-certified display, or pick one explicitly.
  4. Click Start. The control panel minimises and a click-through FSE popup appears on the 3D Vision display. Put on the shutter glasses; you should see stereo separation.
  5. Click the taskbar icon (or right-click the tray icon -> Show panel) to bring the control panel back. Press Ctrl+F8 to hide / re-show the 3D output without stopping. Click Stop to tear down the 3D output cleanly.

Hotkeys

Hotkey Action
Ctrl+F8 Show / hide the 3D Vision FSE window (also kills/spawns the focus watcher)
Shift+F8 Toggle eye-swap (reverses left/right; ~300 ms FSE blink while the presenter restarts)

Both are global - they fire even when the captured game has foreground.

Tray menu

Right-click the system tray icon for: Show/Hide panel, Start/Stop, Quit. Double-click toggles panel visibility. Closing the panel with the X button quits the app (and tears down the FSE popup cleanly).

Settings & log

Smoothness & sync

A 3D Vision panel is frame-sequential: one stereo pair occupies two display refreshes, so a 120 Hz panel can show at most 60 stereo frames per second. A source running at anything other than that rate has to be resampled to it, and an uneven resample is what stutter looks like. The controls below exist to get every clock in the chain onto the same beat.

Which restart does a setting need? Two different things are being set here, and they bind at different moments:

Setting Takes effect
Output sync interval, Max frame latency, FLIPEX next Start - NV3DLib reads them while creating the 3D device
Fast Sync profile, flip-interval flag restart of NV3D-Glass - the driver binds a profile as a process starts up

Output sync spans both: the presentation interval changes on the next Start, but the Fast Sync profile it turns on or off needs the restart, which is why changing it offers one.

NVIDIA driver profile

NV3D-Glass can write NVIDIA driver settings for you, so you don’t have to reproduce them by hand in NVIDIA Control Panel or NVIDIA Inspector. Everything it overwrites is recorded first so it can be put back exactly, including deleting a profile or application entry it had to create.

The Fast Sync profile is owned by the Output sync setting, not by a button. Selecting Vsync off applies it (Fast Sync, 1 pre-rendered frame, maximum-performance power mode) and selecting anything else removes it again - the profile is meaningless without that mode, and having two places to set one thing is how the two get out of step. It asks for confirmation the first time and is silent afterwards; set auto_apply_nvprofile=0 in the INI to disable the coupling entirely.

Fast Sync is not exposed in the standard Control Panel at all: it renders unthrottled and shows only the newest finished frame at each vblank, so you get tear-free output without hard vsync halving the rate when a frame is late. Nothing outside NV3D-Glass’s own profile is touched. A checkbox beside the dropdown adds the undocumented Vsync - Behavior Flags = IGNORE_FLIPINTERVAL_MULTIPLE to that profile - 3D Vision doubles the flip interval to fit a stereo pair into two refreshes, and this is the driver’s knob for that multiplication.

Apply vsync + N fps cap to game is a separate, opt-in toggle, and the single most effective setting for smoothness. It caps the captured game to the panel’s stereo rate (half its refresh) and forces vsync on for it: the cap stops the game drawing frames that can never be shown, and vsync locks its presents to the same vblank train we present on, so each stereo pair carries one whole new frame instead of part of one. It is written into whatever profile the game already belongs to, so that profile’s other settings are preserved, and the same button removes it again. The two are undone independently - switching Output sync away from Vsync off never disturbs a game’s frame cap.

The control sits in the Capture Source section, under Refresh sources, with the target executable named beside it. In Window capture mode that target is exact - the game’s process was resolved at Start. In Katanga mode the protocol carries a texture handle and nothing else, so there is nothing to resolve: pick the process from the Game (for driver profile) dropdown. There is deliberately no auto-detect option - the only thing available to guess from is window focus, and a wrong guess would write driver settings for an unrelated application. Nothing is written until you pick one. The dropdown affects only which profile is written; capture still takes whatever the producer publishes.

A profile change only takes effect in a freshly started process. The NVIDIA driver reads an application’s profile while that application is initialising its graphics DLL, so a game that is already running keeps whatever it started with - restart the game.

This applies to NV3D-Glass itself too, and stopping and restarting the 3D session is not enough: a D3D11 device is created during startup, so our profile is already bound by the time you can change anything. Switching Output sync into or out of Vsync off therefore offers to restart NV3D-Glass, which saves your settings, launches a replacement that waits for this one to exit, and quits.

The applied/removed state is tracked per executable, so capping one game never makes another appear capped, and removing one leaves the others alone.

Both are disabled while a 3D session is live: an elevation prompt stealing foreground from the fullscreen stereo output is exactly the kind of focus fight that destabilises it.

If Vsync off is still selected the next time NV3D-Glass starts, it re-applies the Fast Sync profile at launch (without prompting for elevation) so the mode isn’t left silently inert. If it can’t - because that machine needs admin for it - the Output sync section says so rather than pretending the mode works.

Whether saving needs administrator rights is decided per setting, not per session: the general 3D settings written here go through as a plain user on machines where the 3D Vision stereo settings (StereoProfile and friends, as written by 3DVision4All’s EnableWindowed3D) are refused outright. So NV3D-Glass always tries in-process first and only re-runs that one change in an elevated helper when the driver actually returns access-denied - no prompt when none is needed. If you would rather not let it near your driver profile at all, the equivalent by hand is: cap the game to half your panel’s refresh and turn vsync on for it, and leave Output sync on Vsync on.

To measure any of this, set NV3D_GLASS_PACING=1 and NV3D-Glass logs a once-per-second line with the real tick period, how many ticks captured a frame, and the present worker’s accepted/dropped/duration counters.

Driver profile from the command line

The same profile operations the control panel uses are reachable directly, which is handy for support and for undoing things without launching the UI. Each runs one driver transaction and exits without creating a window:

NV3D-Glass.exe --apply-nvprofile inspect [game.exe]   report what the driver
                                                      currently has (read-only)
NV3D-Glass.exe --apply-nvprofile revert               undo everything on record
NV3D-Glass.exe --apply-nvprofile revert self          undo just the Fast Sync profile
NV3D-Glass.exe --apply-nvprofile revert game game.exe undo just that game's cap

revert with no scope is the way out if the undo record is ever in a state the control panel can’t act on. These write to NV3D-Glass-nvprofile.log rather than the main log, so they don’t disturb a running instance.

Notes

Building from source

Requires Visual Studio 2022 with the Desktop development with C++ workload (v143 toolset, Windows 10 SDK).

git clone --recurse-submodules https://github.com/oneup03/NV3D-Glass.git
cd NV3D-Glass
.\tools\build.ps1

tools/build.ps1 locates MSBuild via vswhere (no Developer Command Prompt needed) and builds the default Release-MT|x64. The vcxproj’s PreBuildEvent builds NV3DLib first (lib only, samples skipped). Pass -Configuration Debug-MT / -Target Rebuild / etc. for other variants. Output: bin\x64\Release-MT\NV3D-Glass.exe.

In VS Code: open the folder, then Ctrl+Shift+B runs the default build task (Release-MT|x64). F5 launches the built .exe under the Visual Studio debugger.

License

LGPL-2.1-or-later. See SPDX headers on individual source files and the LICENSE file at the repo root.

Acknowledgments