OPAQUE Macro compiling on Windows

[nnn911]

When compiling VisRTX 0.13.0 on Windows I get the following error:

FAILED: devices/rtx/device/CMakeFiles/MatteShader_ptx.dir/material/shaders/MatteShader_ptx.ptx
C:\Work\proj-~2\NVIDIA~1\CUDA\v13.3\bin\nvcc.exe -forward-unknown-to-host-compiler -DGLM_ENABLE_EXPERIMENTAL -DNOMINMAX -D_USE_MATH_DEFINES -IC:\Work\proj-deps\VisRTX-0.13.0\build\devices\rtx\device -IC:\Work\proj-deps\VisRTX-0.13.0\devices\rtx\device -isystem C:\Work\proj-deps\anari\include -isystem C:\Work\proj-deps\anari\include\anari\backend -isystem C:\Work\proj-deps\VisRTX-0.13.0\build\deps\source\optix_headers\include -isystem "C:\Work\proj-deps\NVIDIA GPU Computing Toolkit\CUDA\v13.3\include" -isystem "C:\Work\proj-deps\NVIDIA GPU Computing Toolkit\CUDA\v13.3\include\cccl" -isystem C:\Work\proj-deps\VisRTX-0.13.0\devices\rtx\external\glm\include -isystem C:\Work\proj-deps\VisRTX-0.13.0\devices\rtx\device\..\external\nanovdb\include -Xcompiler=/Zc:preprocessor -Xcompiler="-O2 -Ob2" -DNDEBUG -std=c++17 "--generate-code=arch=compute_75,code=[compute_75]" -Xcompiler=-MD --expt-relaxed-constexpr --extended-lambda -Xcudafe=--diag_suppress=20012 -Wno-deprecated-gpu-targets -rdc=true --entries __direct__callable__evalSurfaceMaterial -MD -MT devices\rtx\device\CMakeFiles\MatteShader_ptx.dir\material\shaders\MatteShader_ptx.ptx -MF devices\rtx\device\CMakeFiles\MatteShader_ptx.dir\material\shaders\MatteShader_ptx.ptx.d -x cu -ptx C:\Work\proj-deps\VisRTX-0.13.0\devices\rtx\device\material\shaders\MatteShader_ptx.cu -o devices\rtx\device\CMakeFiles\MatteShader_ptx.dir\material\shaders\MatteShader_ptx.ptx -Xcompiler=-Fddevices\rtx\device\CMakeFiles\MatteShader_ptx.dir\,-FS

C:/Work/proj-deps/VisRTX-0.13.0/devices/rtx/device\gpu/evalMaterialParameters.h(47): error: expected an identifier
    if (mode == AlphaMode::2 )
                           ^

C:/Work/proj-deps/VisRTX-0.13.0/devices/rtx/device\gpu/evalMaterialParameters.h(47): error: expected a ")"
    if (mode == AlphaMode::2 )

I assume it happens because AlphaMode::OPAQUE is broken by the OPAQUE macro defined elsewhere:

// From evalMaterialParameters.h
VISRTX_DEVICE float adjustedMaterialOpacity(
    float opacityIn, AlphaMode mode, float cutoff)
{
  if (mode == AlphaMode::OPAQUE)
    return 1.f;
  else {
    if (mode == AlphaMode::BLEND)
      return opacityIn;
    else
      return opacityIn < cutoff ? 0.f : 1.f;
  }
}

One fix is to undefine OPAQUE before adjustedMaterialOpacity, however, I'm not sure if this has any unintended side effects.

#ifdef OPAQUE
#undef OPAQUE
#endif

System details:

MSVC

Microsoft (R) C/C++ Optimizing Compiler Version 19.51.36246 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

NVCC

nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2026 NVIDIA Corporation
Built on Fri_Apr_24_19:26:09_Pacific_Daylight_Time_2026
Cuda compilation tools, release 13.3, V13.3.33
Build cuda_13.3.r13.3/compiler.37862127_0

[tarcila]

Hello @nnn911,

Thanks for the report. The next_release branch has been updated with fixes for that very issue.
Can you give it a shot and confirm this works?

One fix is to undefine OPAQUE before adjustedMaterialOpacity, however, I'm not sure if this has any unintended side effects.

If you need to stay on the latest release, then this is a proper workaround which should be safe.