There are effectively two ways that you can use NanoGUI in C++: have NanoGUI initialize and manage the OpenGL context (and GLFW), or you do it manually.

  1. If you are letting NanoGUI take over, you must call Function init before trying to do anything else. If you are managing OpenGL / GLFW yourself, make sure you avoid calling this method.
  2. Create an instance of Class Screen (or a derivative class you have written).
    • NanoGUI managed OpenGL: call the explicit constructor.
    • Self managed OpenGL: call the empty constructor.
  3. Add any Widgets, Buttons, etc. you want to the screen instance, and call the nanogui::Screen::setVisible() and nanogui::Screen::performLayout() methods of your instance.
  4. Now that everything is ready, call Function mainloop.
  5. When all windows are closed, this function will exit, and you should follow it up with a call to Function shutdown.
NanoGUI Managed OpenGL / GLFW:
 Refer to Example 2 for a concise example of what that all looks like.
Self Managed OpenGL / GLFW:
 Refer to Example 3 for an as concise as possible example of what you will need to do to get the Class Screen to work.


The Python interface is very similar to the C++ API. When you build NanoGUI with CMake, a python folder is created with the library you import nanogui from. Though there are implementation details that differ greatly, the documentation and build process for the Python side is roughly the same. Refer to the Examples and compare the source code for the two.

Example 3 highlights the more notable differences between the APIs. Specifically, that managing GLFW from Python has no meaning, as well as the main loop for Python can easily be detached.