WPF provides a number of services for transforming 3D points into 2D space and vice versa. This can be invaluable when apps require interaction between 2D and 3D content. For example, imagine writing a 3D molecule viewer with 2D text labels for the various atoms comprising the molecule. You’d like the text labels to be drawn as a layer on top of the 3D content, but you want the text to follow the atoms as the model is rotated. With these coordinate space transformation services, you can achieve this. Let’s take a look at the 3D transformation APIs provided and how to use them.