2.6 KiB
Explicit Windows d4r backend
Base: OptiScaler 45a2001303ddff632e279f77aef85ceede5832cb (2026-09-30).
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.