Portable DLSS neural execution bridge

DLSS Bridge inserts neural rendering into a supported game's temporal upscaling pipeline. The neural workload can run on the game GPU or on another NVIDIA GPU, and the result returns to the game before post-processing, UI, and presentation.

The validated Linux path uses a Vulkan NGX title through Proton with two RTX 3090 GPUs. Native Windows uses the same launcher and injected host without Wine.

Supported path

The validated release path is 64-bit Windows Vulkan games that expose NVIDIA NGX:

• Steam Proton on Linux
• Native Windows
• Same-GPU or secondary-GPU neural execution
• RTX 3000, 4000, and 5000 series cards when runtime capability checks pass

Direct3D 11 and Direct3D 12 capture, multi-viewport split-screen (up to 4, on demand, no per-game setup), Frame Generation coexistence, Ray Reconstruction on D3D12, and child-process follow (--follow-children TARGET.exe) for launcher-spawned games are implemented but untested — see docs/known-limitations.md. There are no per-game profiles: the API is auto-detected and only GPU placement is selectable (--profile same-gpu / secondary-gpu).

Native Linux games and final-frame processing are planned backends. Streamline-native titles are covered by the NGX-level hooks with no separate backend. Anti-cheat-protected processes are never injected.

Install

Linux:

curl -fsSL https://github.com/numsu/dlss-bridge/releases/latest/download/install.sh | sh

Windows:

1. Download and run dlss-bridge-windows-x86_64-setup.exe from the latest release.
2. Restart Steam.

Set the Steam launch option:

dlss-bridge run -- %command%

The launcher attaches DLSS Bridge from an isolated user-state session and removes that session when the game exits. The game directory and Wine prefix remain untouched. Omit the prefix to launch normally.

You can configure the same option without opening Steam's Properties dialog. Exit Steam first, then run:

dlss-bridge steam configure APPID --profile same-gpu

Restore the previous setting with dlss-bridge steam remove APPID.

Heroic configures the same way and additionally ensures Proton exposes the NVIDIA GPU (PROTON_ENABLE_NVAPI=1, PROTON_HIDE_NVIDIA_GPU=0) so DX11/DX12 titles show their DLSS option:

dlss-bridge heroic configure GAME --profile same-gpu

Both installers download and checksum-verify the pinned NVIDIA neural runtime; installation fails if it is unavailable or invalid. The runtime is not bundled in this project’s release artifacts. Rerun the Linux installer or run a newer Windows setup EXE to update. Runtime files, settings, and collected logs remain in user state.

See Installation and updates for requirements, GPU selection, conflicts, removal, and troubleshooting.

Toggle neural rendering in game

Press Ctrl+Shift+N to show or hide the neural effect. Capture, transport, and the private DLSS upscaler and neural model remain active, so this provides an immediate visual comparison without rebuilding the feature or returning to the game's original upscaler. OptiScaler displays the applied state on screen. The session log records each request and reports state-separated GPU timing once it has enough completed samples.

GPU selection

Automatic selection prefers another compatible NVIDIA GPU and uses the game GPU when no secondary adapter is available.

dlss-bridge run --profile same-gpu -- %command%
dlss-bridge run --profile secondary-gpu -- %command%

Runtime behavior

The runtime intercepts the game's NGX temporal-upscaling call (Vulkan, D3D11, or D3D12), recreates its frame contract in a private D3D12/NGX session, executes neural rendering, and reinserts the result before downstream rendering. Frame Generation features pass through natively; Ray Reconstruction inputs are transported on the D3D12 path.

After the first private neural frame completes, neural-only operation is latched:

• the game-side DLSS evaluate is not executed;
• a late result repeats the last completed neural image;
• a frame that cannot enter the bridge reports NGX failure;
• a permanent bridge failure remains visible instead of silently resuming the game's original DLSS path.

If the game never enables DLSS, the bridge stays idle — there is no contract to mirror — and after ~512 presents (Vulkan) or submissions (D3D12) with no NGX feature created it logs one DLSS appears disabled in-game hint. The notice fires only once frames are actually flowing, never during startup.

Configuration

Policy is stored in TOML. The default profile uses automatic GPU placement, a four-slot ring, a two-frame pipeline, and the unified neural queue.

[feature]
placement = "before_sr"
working_scale = 1.0
passes = 1

[execution]
mode = "auto"
compute_adapter = "auto"

[transport]
neural_queue = "unified"
ring_slots = 4
neural_pipeline_frames = 2

Custom profiles can override these values:

dlss-bridge run --profile /absolute/path/custom.toml -- %command%

GPU generations are not used as compatibility switches. Adapter identity, driver and API support, model compatibility, resource formats, feature creation, and transport probes determine whether a route is usable.

Architecture

The implementation provides:

• Vulkan, D3D11, and D3D12 NGX capture through suspended-process injection, a Vulkan layer, or a ReShade add-on
• Child-process follow for launcher-spawned games
• Same-GPU D3D12 NGX execution
• Secondary-GPU execution through directional host-memory staging
• In-frame reinsertion on all three capture APIs
• A versioned C ABI for capture, executor, transport, and host backends
• Shared configuration, scheduling, adapter identity, and telemetry policy
• Linux/Proton and native Windows launch wrappers

See Portable architecture for interfaces, frame ownership, synchronization, and planned backends. External dependencies records the version and purpose of every third-party runtime, build, and test component. See Known limitations for current coverage and remaining extraction work.

Build and test

Build the Windows bridge DLLs in Docker:

scripts/build-vk-bridge.sh

Build a Linux release archive:

VERSION=vVERSION packaging/build-linux-package.sh dist

Run the core checks:

g++ -std=c++17 -Wall -Wextra -Werror -Icore/include \
  core/src/runtime.cpp core/src/components.cpp tests/unit/runtime_test.cpp -o /tmp/dlss-runtime-test
/tmp/dlss-runtime-test
g++ -std=c++17 -Wall -Wextra -Werror -Ibridge/dlss5-vk-bridge/src \
  tests/unit/dlss_off_gate_test.cpp -o /tmp/dlss-off-gate-test
/tmp/dlss-off-gate-test
PYTHONDONTWRITEBYTECODE=1 python3 tests/unit/controller_test.py
gcc -std=c11 -Wall -Wextra -Werror -Iinclude \
  tests/unit/abi_c_test.c -o /tmp/dlss-abi-test
/tmp/dlss-abi-test
scripts/bridge-load-test.sh

Tagged releases build the Linux archive and native Windows setup EXE through the release workflow.