QT + OpenCV error : C1083 opencv2/opencv.hpp no such file or directory

In Qt, setting of "include and lib path" is configured in the .pro file.

For example :

INCLUDEPATH += C:\opencv300rc1\opencv\build\include
LIBS += C:\opencv300rc1\MyBuild\lib\Debug

But in my case, I can not find the reason of error "C1083 opencv.hpp no such file or directory..."

I tried various attempts, but I don't know why error occur.

But I found the way of to avoid the error.

That is using build setting tab (ctrl + 5).

In build environment, add opencv path INCLUDE and LIB.

I solved the problem in this way.

Please note.