To build the Qt sources by your own you have to do the following steps:

1. Download and install Visual Studio 2015. I took the Community edition.
2. Download and install Qt. I took the Visual Studio 2015 Desktop version.
3. Download and install Python. It has to be installed to compile QML.
4. Open the Visual Studio ‘Developer Command Prompt for VS2015’: Windows Start – Visual Studio 2015 – Developer Command Prompt for VS2015
5. Than run the following command chain

   >> cd "Path/to/the/Qt/source/folder/" (in my case C:\Qt\5.7\Src)
   
   Follow this link to get more information about the configuration parameters. In my case I recompile the source code to use OpenGL.
   
   >> configure -opengl -desktop -platform win32-msvc2015
   
   The supported platform parameter could be found in this directory: 'C:\Qt\5.7\msvc2015_64\mkspecs'. The parameter title is the directory name.
   
   >> nmake
   
   Now lay back and drink a coffee. It will at least last a hour...

6. For using OpenGL insert the following to your pro file

   QT += qml quick opengl
   LIBS += 'C:/Program Files (x86)/Windows Kits/10/Lib/10.0.14393.0/um/x64/OpenGL32.Lib' (in my case, just search for the OpenGL32.Lib)

7. Congratulations! Now you can start with QML and OpenGL!