Creating a camera

One of the advantages of 3D graphics over 2D graphics is the possibility of walking through the virtual scene and rotating objects in a way we do in real life. So the user feels as though he or she were inside that scene, observing real objects. The navigating in space is achieved using a camera. It is a special object that controls the way of projecting 3D points to 2D points on the screen.

Tip

There are two types of projections from 3D to 2D:

• Perspective projection: Far-off objects look smaller than nearby objects. This is the type of projection used in openFrameworks by default.
• Orthogonal projection: The visible size of an object does not depend on the distance to the viewer.

In openFrameworks, a camera can be represented by the ofCamera class or the ofEasyCam class. The first class is a quite general camera class, and the second one extends it by implementing a number of additional capabilities, including handling mouse events for controlling the camera.

Tip

To enable orthogonal...