编译NvRTX焦散分支Unreal Engine后缺失dxgi.lib求助

I’ve run into nearly identical third-party library path issues when compiling custom UE branches before—those vague "unresolvable library" warnings almost always point to a broken path reference or missing files. Here are actionable steps to fix the dxgi.lib error:

1. Verify Third-Party DirectX Library Completeness #

The NVIDIA branch might not include the full DirectX third-party files (common if submodules weren’t cloned properly, or the repo uses .gitignore to exclude large precompiled libs).

• First, check if the path ThirdParty/Windows/DirectX/Lib/x64/ actually exists in your cloned engine directory. If it’s missing or empty:
  • Re-clone the repo with submodule support using git clone --recursive https://github.com/NvRTX/UnrealEngine/tree/NvRTX_Caustics
  • Or, copy the complete DirectX Lib folder from a working Unreal Engine source build (official 4.x branch matching the NVIDIA branch’s base version) into the corresponding ThirdParty directory.

2. Fix Library Path References in the DX11 Module #

The warning message hints that the DX11 module is using an unqualified path for dxgi.lib. Let’s update the build configuration:

• Navigate to Engine/Source/Runtime/DX11/DX11.build.cs
• Modify the library reference to use absolute paths via UE’s built-in directory variables:

  // Replace any hardcoded relative paths with this
  string DirectXLibDir = Path.Combine(EngineDirectory, "ThirdParty", "Windows", "DirectX", "Lib", "x64");
  PublicAdditionalLibraries.Add(Path.Combine(DirectXLibDir, "dxgi.lib"));
  

• Alternatively, to suppress the warning and use system-style path searching, add the directory to PublicSystemLibraryPaths:

  PublicSystemLibraryPaths.Add(Path.Combine(EngineDirectory, "ThirdParty", "Windows", "DirectX", "Lib", "x64"));
  // Then just reference the library name without the full path
  PublicAdditionalLibraries.Add("dxgi.lib");
  

3. Manually Add the Path to Visual Studio’s Linker Configuration #

If the project generation script doesn’t pick up the path correctly, manually add it to your VS project:

• Open the UE4Editor solution in Visual Studio 2017
• Right-click the DX11 module project (under the Runtime folder) → Properties
• Go to Linker > General > Additional Library Directories
• Add the path $(EngineDir)/ThirdParty/Windows/DirectX/Lib/x64 and click OK

4. Clean and Regenerate Project Files #

Cached build artifacts or outdated project files often cause these issues. Do a full clean:

• Delete the Engine/Binaries and Engine/Intermediate folders
• Run Engine/Build/BatchFiles/GenerateProjectFiles.bat to regenerate the VS solution
• Do a Clean Solution in Visual Studio, then rebuild the entire engine from scratch (skip incremental builds for this fix)

内容的提问来源于stack exchange，提问作者Bachalo