as many people asked privately, it seems we should make it clear here that

BOTH qmake and cmake can be used to build V3D!!

qmake is more straightforward but cmake is also very easy once you set up the building environment.

If you choose to use qmake, then what you can do to build is to simply run "build.macx", "build.linux", or "build.bat" (this one is in the "v3d_main" folder) after you check out the V3D source code.