No, it's not a separate install.
Set your camera where you want it to start - Once you've got it positioned where you like it, click the symbols next to position and rotation (theres a button with a symbol and an "A") click the button and click "Set Animation Key". Then, at the bottom, move the slider to another frame, and re-position the camera, and re-set the animation keys. Terragen will calculate a curve in-between the two animation keys you set to keep the camera movement smooth.
Hope this makes sense.
