CMake Error: The following variables are used in this project, but they are set to NOTFOUND.

CMake Error: The following variables are used in this project, but they are set to NOTFOUND.错误引发的深思：

关于opencv2.4.13.2在cmake（3.9.6版本）编译为( vs IDE 32位架构下支持的)opencv_gpu包，

过程中，选择 Visual Studio 14 2015（注意与Visual Studio 14 2015 Win64区别）

我的cuda版本：win10 8.0 x86_64支持。

出现CMake Error: The following variables are used in this project, but they are set to NOTFOUND.的问题！！！

缺少库：

opencv_dep_CUDA_cufft_LIBRARY

opencv_dep_CUDA_nppc_LIBRARY

opencv_dep_CUDA_nppi_LIBRARY

opencv_dep_CUDA_npps_LIBRARY 

参考链接：https://stackoverflow.com/questions/33097558/cmake-cuda-libraries-not-found-when-compiling-opencv

Thanks to tips from Drop in the comments, I solved this problem. In order to close this question, I'm answering my own question.

It's a "Win32 or x64" architecture problem. Since NVIDIA only provides cufft, nvblas, nppc, nppi, npps libs for x64, it's naturally impossible for CMAKE to find these libs for configuring a Win32 OpenCV library.

My solution was to choose Visual Studio 11 Win64 instead of Visual Studio 11 as generator in CMAKE. So that CMAKE will automatically load libs from <CUDA_DIR>\lib\x64 rather than <CUDA_DIR>\lib\Win32. Further more, I also need to load all the other libs required by OpenCV in 64 bit version, such as OpenGL. I will also need to compile OpenCV in x64 architecture. All the code I'm going to write in the future will have to build and debug in x64 only.

Notes：Nvidia 不提供x64的库 cufft、nvblas、nppc、nppi、npps.

原VS Debug-x64架构下的opencv2.4.13.2（gpu支持）

1 VC++目录--包含目录：
E:\opencv2.4.13\cuda_vc14\ install\include
E:\opencv2.4.13\cuda_vc14\ install\include\opencv
E:\opencv2.4.13\cuda_vc14\ install\include\opencv2

2 VC++目录--库目录：
E:\opencv2.4.13\cuda_vc14\ install\x64\vc14\lib
C:\Program Files\ NVIDIA GPU Computing Toolkit\CUDA\v8.0\lib\x64

3 系统变量
  E:\opencv2.4.13\cuda_vc14\ install\x64\vc14\bin

note：配置完系统变量，重启（重启vs或windows）才能生效！！！

4 链接器--输入--附加依赖项：
opencv_ml2413d.lib
opencv_calib3d2413d.lib
opencv_contrib2413d.lib
opencv_core2413d.lib
opencv_features2d2413d.lib
opencv_flann2413d.lib
opencv_gpu2413d.lib
opencv_highgui2413d.lib
opencv_imgproc2413d.lib
opencv_legacy2413d.lib
opencv_objdetect2413d.lib
opencv_ts2413d.lib
opencv_video2413d.lib
opencv_nonfree2413d.lib
opencv_ocl2413d.lib
opencv_photo2413d.lib
opencv_stitching2413d.lib
opencv_superres2413d.lib
opencv_videostab2413d.lib