As I had no access to Karstens game loop, I wrote an own for my Physics test and tried to wrap it into a class. Tried. A error occured that would cause a segmentation fault. Comment The three new Lines in Main in to see the changes. (Has to be a meta-error as the game loop worked with global variables ... and yes, this "std::thread t(&Game::loop, this);" is a valid way to call a member function in a separate Thread.)