The camera

In Chapter 2, Your Point of View we compared creating games to making a video recording. Your video camera captures a part of the view in front of you. If objects move into or out of that field of view, they are no longer in the video recording.

3D games use a camera as well. OpenGL allows you to move the game camera on six axes: up, down, left, right, in, and out. As you move the game camera, the objects that are in its view change.

Let's say that you center the camera on the car in the scene and pan to the left or right. The car will move in and out of the field of view. Of course the same occurs if you pan the camera up or down. Move back (or zoom out) and the car appears smaller. Move forward (or zoom in) and the car appears larger. Tilt the camera and the car will appear to be going uphill, downhill, or even appear upside down!

Remember those home movies?

Remember those home movies where the whole scene would jump around as the camera moved? Obviously, the position and movement...