Chapter 3: Animation For Dummies
The director should tell you all this. If you are the director, you should know all of this.
How you do it is the step-by-step approach. Analyze the action. Act it out physically if you can, or at least in your mind. Have a stopwatch in your hand. First, time the overall action. Often you will be given an exact scene-length by the director. Then, step by step, break down the action into logical sections and bits. Your rough drawings or computer positions will then be anchored to exact frame numbers. In your scene, you will have a precise number of film or video frames.
The fact that your scene will be shown at the constant rate of 24 or 25 frames per second is what makes animation possible. Think of that steady frame rate as your (very fast!) rhythm section. What you will do with your animation poses and spacing against this steady frame rate is your counterpoint. Closely spaced phases of motion will appear to move slower when played back, and widely spaced phases will appear to move faster. Here is your basic animation tool in a nutshell: You are doing a counterpoint to a steady beat!