Players extract one ZIP into the game folder, copy their two NVIDIA DLLs, and start the game from Steam, Epic or a shortcut. No launcher script is needed; settings live in d4r\d4r.ini. - Shim player mode: when the launcher has not set D4R_HIP_ROOT and d4r.ini sits beside the shim, derive the backend environment from it. Codegen flags stay at the Windows-validated values. NVIDIA DLLs must match an exact SHA256 in dll-pins.txt, with "you have X, you need Y" errors. Rejects a vkd3d/Wine d3d12.dll and code objects built for another GPU. [DLSS] Model accepts K or M and is applied by rewriting the render preset hints. - d4r.ini exposes only options that exist on Windows: Model, AsyncInterop, ValidateOutput, Log, CacheDir. Invalid values fall back with a note in d4r_nvngx.log. - d4r_nvngx_loader: one _nvngx.dll for all GPUs. It matches the game's adapter by LUID and loads _nvngx_<arch>.dll from the same folder. - OptiScaler patch 0006: relative NvngxPath/NvngxDlssPath/ NvngxFeaturePath resolve against OptiScaler's folder. - package-windows-release.ps1 builds the release from the per-target game packages and refuses mixed targets or differing shared runtimes. - Tests: test-player-config.ps1 (ini and DLL-pin decisions, loader selection on the local GPU) and test-windows-release-package.ps1.
Explicit Windows d4r backend
Base: OptiScaler 45a2001303ddff632e279f77aef85ceede5832cb (2026-09-30).
0004 serializes D3D12 device hook installation/removal and guards recursive
device discovery while the d4r command backend installs. The previous frontend
can start two installations, fail a Detours transaction with 0x10dd, clear
live original-function pointers and call null. This was reproduced in the
numeric-ID standalone harness; no game was required.
0005 propagates numeric Init/Init_Ext failures for the explicitly selected
external backend, matching the existing ProjectID behavior. FeatureNotFound
must fail initialization instead of being hidden until repeated CreateFeature
attempts. Libraries.NvngxDlssPath takes a directory, not the DLL filename;
the Windows installer and standalone runner now use that directory.
The modifications to OptiScaler are GPL-3.0, matching its upstream license.
No NVIDIA DLL is supplied or patched.
0001 introduces [DLSS] AllowExternalBackend=true, default false. Set
[Libraries] NvngxPath to the absolute directory containing the Windows d4r
shim as _nvngx.dll. Discovery requires its GPU-free ABI-1 marker. Physical
adapter support is queried through the bridge's D3D12 requirements API after
DLL startup; vendor, LUID and HIP architecture are retained.
The configured D4R_NGX_CORE absolute path bypasses game-facing NGX DLL
redirection. The external backend loads its own NVAPI provider. An explicitly
selected external DLSS backend reports initialization/load errors instead of
silently switching to FSR. The patch fixes the upstream loader's filesystem
exception by making IsSubpath a lexical check, and retains a PDB for diagnosis.
0002 installs the command backend at D3D12 device discovery, before NGX Init
and before OptiScaler's own method hooks. Command signatures created during
game startup therefore retain their public argument descriptions for replay.
The standalone runner's -EarlyIndirectProbe exercises this startup order.
0003 preserves the Project ID and engine identity through OptiScaler's
older Init_with_ProjectID entry point used by its XeSS/FSR inputs. It also
propagates an explicit external backend initialization failure. Reproduce
with the D3D12 runner's -NgxAbi project-legacy.
Build with Microsoft Build Tools 2022, v143 and Windows SDK 10.0.26100:
.\scripts\windows\build-optiscaler-windows.ps1
The script clones the pinned source if absent, checks/applies the patch,
initializes pinned submodules, invokes MSBuild and writes the DLL, PDB, license
and build metadata into dist/optiscaler-windows-d4r. Existing source is not
reset. The upstream packaging post-build event is disabled for this build.
The official bootstrapper is https://aka.ms/vs/17/release/vs_buildtools.exe;
install the Microsoft.VisualStudio.Workload.VCTools,
Microsoft.VisualStudio.Component.VC.Tools.x86.x64 and
Microsoft.VisualStudio.Component.Windows11SDK.26100 components. The audited
local build uses MSVC 14.44.35207 / Build Tools 17.14.
For standalone verification add
-OptiScalerDll <absolute-dist-path>/OptiScaler.dll -CaptureExceptions
to the documented K/M runner. Its private INI selects DLSS, disables frame
generation and keeps RestoreComputeSignature, RestoreGraphicSignature and
ExtendedStateRestore false. Use -RequireNativeNetwork; finite output alone
cannot distinguish DLSS from an unwanted FSR replacement.