Hands-On High Performance Programming with Qt 5

Qt 3D

Qt 3D is a different take on OpenGL rendering—another one! It offers both QML and C++ APIs, and provides a high-level OpenGL API, but it uses a frame graph instead of QML's scene graph for rendering.

The difference is that in QML, there is a hard-coded renderer for the scene graph, which renders the scene in a predefined way, optimized for 2D rendering and using rather standard rendering methods. However, there is a steady stream of innovations and new approaches in 3D rendering, and Qt 3D trying to design a framework that is both more flexible and more extensible.

As a result, the frame graph doesn't specify what objects are to be rendered as the QML scene graph does. Rather, the position of a node in the frame graph tree will determine ...