Sure, there are no angry directors yelling "cut!", no camera crew, no temperamental actors locking themselves in their dressing rooms. But you still need a camera's "eye" in the virtual scene, to capture your animation from any angle and zoom that you desire.
So..How Do You Get a Camera Inside Your Compuer?
Through use of virtual cameras. Virtual cameras, of course, aren't really cameras, but they serve the same purpose. Instead of complicated arrays of lenses, film, and recording devices, the cameras in your three-dimensional space are a set of mathematical calculations that determine what your rendered output will be based on the location of the camera, its field of "vision" based on the aspect ratio set in your render options, any motion assigned to the camera, and the lighting set in your environment.
Is It Like a Real Camera?
Just like a real camera, virtual cameras can pan, zoom, rotate, and dolly; however, with virtual cameras you have many more options for how the motion will be controlled, and are much easier to set up. Instead of using a vast array of equipment, you can add a virtual camera to your scene just by clicking in the appropriate spot using your 3D modeling software's camera tool, and then using your mouse to drag and rotate it to position it appropriately over your entire animation or in different positions for various keyframes.
You can move the camera manually yourself, adjusting its position frame-by-frame or telling it to move from point A to point B over a set number of frames; or, you can create a motion path for it, and assign it to follow that path by "attaching it" so that it rides along the path like a roller-coaster on its tracks. This technique is how animators achieve those dizzying, hyper-fast, twisting contortions of racing camera motion that seem to put you right in a first-person perspective of the on-screen action.
But Why Do I Need a Camera in My Scene? Can't I Just Tell the Computer to Record What I See?
No. Your computer and your 3D rendering software needs a vehicle by which to interpret what you're seeing, and control how the lighting and shapes will be rendered from particular angles. You can have multiple cameras in a scene, and then select the one that you want your animation to render from when you get to the stage of video output.
When That's Done, How Does it Get to My TV/Movie Screen?
Once the camera has "recorded" the action and output it as a digitally rendered movie file, then the animated action can be spliced in with any live action or traditional animations used in the project, in a digital video editing environment such as Adobe Premiere[/url]. Once everything is spliced together, it's transferred to a viewable media format--film reel, video, DVD, etc.--and there you have it; that's how those animated sequences make it from the digital modeling environment to your screen.