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.