The key to animation in After Effects CS5 is keying the timeline or more properly, setting keyframes in the timeline. How do you get started? Using graphic icons, stopwatch, and time indicator on the timeline you will be creating animation on your first outing.As you review the timeline panel with resources on the left side and the timeline on the right, you see your composition time displayed as the length of your composition. For this exercise let’s create a composition, choosing ‘Web Video 320 x 240’ from the preset compositions and we’ll call it ‘gravity’. Set your movie duration to 10 seconds by entering 10:0. This designate 10 seconds and 0 frames.I chose a light color for my composition background color, the last option presented in the new composition window. We’re going to animate a ball rolling down a ramp, doing some physics, obeying gravity.
We can create a simple ramp using the rectangle tool and it should be safe to ‘eye this in’. Right click in the timeline resource area on the left, hover over the ‘New’ option, and click on ‘Shape Layer’. About midway on the top tool bar you see a shape with a pull down arrow tag in the lower right of this icon display. Clicking the arrow presents the shape options available to you.Choose rectangle, place your cursor in the composition area, on the left, and draw a rectangle. If you click, then drag to the right creating just a wee bit of depth, you will create a ramp with a little thickness to it. Now create a ball. Under the same shape option choose ellipse tool and hold the shift key while drawing it. This will create a perfectly round circle. In fact you can draw your ellipse dragging out your mouse, then click the shift key off and on and see it become then discard the circle ‘perfect roundness’ the shift key provides. check this site out
Now you have a ball and a ramp. Great start! I hope you placed your ball to the left, on top of your ramp as it would be in real life. Now click on your ball layer, click the layer open with your ‘twirly arrow’, do the same with the transform layer and click the stop watch next to the ‘Position’ attribute.You immediately see a little golden diamond on your timeline. This is a keyframe and you will become very familiar with keyframes. This tells After Effects to record a value, typically a change and here you have recorded the beginning position of your ball at the beginning of your composition.Now move your ball to the end of the ramp. You can choose the arrow tool on the far left of the tool panel and simply ‘pick it up’ and move it graphically. Notice the ‘x,y’ value changes next to your position when you do this. You could move your ball to the end of the ramp by adjusting the ‘x’ value in your resource area, increasing its value until the ball is at the end of the ramp.