Animating the Sketch

It's time to animate the car sketch so it appears to be drawn onscreen. Instead of animating the lines in the frame that you captured from the Saleen_Car_07 footage, you'll animate a continuous paint stroke that you'll draw with the Vector Paint effect. The paint stroke will serve as a matte, which you'll animate to reveal the car's sketch over time:

1.	Rename the Car (0;00;03;00) layer to AniSketch in the Car composition.
2.	Apply Effect > Paint > Vector Paint to the AniSketch layer. Expand the effect's Brush Settings group, and then set the effect's Radius to 7.0. This brush size will make it easy to cover the entire width of the lines you created with the Cartooner effect. Set the effect's color to something other than white or black so you can make sure you paint over all the white lines in the car sketch and can see your paint strokes over the black background. Note Now that you've applied the Vector Paint effect, notice that Vector Paint tools appear in the upper-left corner of the Composition window. The tools appear only when you have the Vector Paint effect selected in either the Timeline or Effect Controls window. The Vector Paint effect's tools and properties
3.	Using the effect's Paint tool and Paint brush, trace the car line in the AniSketch layer at time 0;00. Don't release your mouse button until you've traced over every line; trace the car body first and then the accents. The resulting car outline will look pretty messy. Start the paint stroke where the arrow is pointing in this illustration. The result of painting over the car lines with the Vector Paint tools
4.	Go to time 3;00, and set the Vector Paint effect's Playback Mode to Animate Strokes. When you change the Playback Mode, a new Playback Speed effect property appears, and a short fat stroke appears over only a small part of the car outline.
5.	Still at time 3;00, scrub the Playback Speed value until the fat paint stroke completely covers the car outline. You want to find the minimum value that covers the outline completely so there is no delay in the animation when it transitions to the movie layer.
6.	Set the Composite Paint option to As Matte. Now you should see the car sketch instead of the Vector Paint stroke.

Click the Ram Preview button in the Time Controls palette to view your animation. The car's sketch should appear to be drawn onscreen by an invisible hand, followed by the footage of the car. If you need to adjust the paint stroke, you must retrace the entire car outlineyou can't adjust the stroke as you can other paths in After Effects.