This tutorial assumes you are familiar with the basics of After Effects, such as keyframing, previewing animations, and applying motion blur. If you are unfamiliar with these things, by all means continue, but be ready to do some consulting with the book or online help!
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Four sections follow:
1. a quick sketch
2. a quick smooth
3. subtle adjustments
4. add another car
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- - - - - a quick sketch - - - - -
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| We are going to make cars race around a track using Motion Sketch and the Smoother. To see the a sample movie of what we are making, click here. |
- Download the project files, and open the START HERE.aep file.
- Select the RcCar.psd layer in the motionSketch composition.
- Find the Motion Sketch window. If it is not already open, you can find it under Window --> Motion Sketch.
- Make sure that Capture Speed is set to 100%, and that show wireframe and keep background are both selected.
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Once you click Start Capture in the Motion Sketch window, the mouse cursor turns into a crosshair.
- Click on the car, and drag your mouse around the track as if you were driving it around the track. The car will not move with your mouse. But pretend it is.
- After Effects records the POSITION and the TIMING (or SPEED) of your motion.
- Race around the track for the full 15 seconds. If you release the mouse button, it will stop recording. If that happens before the 15 seconds are up, undo and try it again.
Check out the position attribute of your RcCar.psd layer. There are now about 450 keyframes, one per frame for 15 seconds. After Effects has sketched your motion!
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If you preview your animation now, you'll probably notice that the car isn't turning at all. This is easily remedied by enabling the Auto-Orient switch for the layer:
- Select the RcCar.psd layer in the motionSketch composition.
- Choose Layer --> Auto-Orient.
- Select Orient Along Path in the Auto-Orientation Window.
- Now if you preview your animation you will see the car more or less pointing in the right direction.
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 click to enlarge
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- - - - - a quick smooth - - - - -
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At this point you might be thinking that your little car is a little too shaky as it moves. This is a common problem with motion sketch: Our mouse-made motion, while definitely not "computer-generated-looking," often is too bumpy for comfort. We will use The Smoother plug-in to fix this problem:
- Navigate to the position attribute of the car layer.
You can do this quickly by selecting the layer and pressing the 'p' key
- Click on the word 'position' under the car layer. This automatically selects every position keyframe for that layer.
- Find The Smoother window. (Window--> The Smoother)
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The Smoother looks at the overall animation of the selected keyframes, and tries to match it using fewer keyframes. By increasing the Tolerance level, you tell it essentially to use fewer keyframes. A higher tolerance number makes a smoother, though usually less accurate, motion. A lower number is bumpier but more faithful to the original animation.
- Double check that all your position keyframes are selected.
- Enter a Tolerance value and click apply.
- Preview your animation. If you are happy with it, continue. If not, undo and try again.
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Here are my position keyframes before applying The Smoother:
And here they are after applying The Smoother:
NOTE: Whereas Motion Sketch only works for the position attribute, The Smoother will work for other attributes as well, such as rotation and anchor point. The Smoother is a very handy tool to keep in the back of your mind as you are working on your animations.
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- - - - - subtle adjustments - - - - -
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At this point, you may want to do some manual adjusting of your car's motion. It is much easier to do now that the sketch has been smoothed.
Move different keyframes a little, or adjust the bezier handles to change the shape of a curve a little. Scoot the keyframes around in time to make the speed how you like it.
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- - - - - add another car - - - - -
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| Now that you are a racin' sketchin' smoothin' expert, bring the RcCar1.psd into your composition and let it race around the track as well. Try to adjust the keyframes so it never collides with the first car.
You will notice that as you Motion Sketch this new car, the red car does not race around the track. This is because Motion Sketch will only show a static background as you sketch. Thus you will have to make your best guess, then adjust keyframes afterwards.
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Render your animation and enjoy!
see the final movie (472 kb)
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Ben Unguren is a freelance motion graphics designer and documentary filmmaker in Provo, Utah.
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