Looping Pan Backgrounds

Follow these steps and you'll soon create a looping pan background effect of your own.

This effect is useful when you have a character running or car moving quickly, so that you don't have to draw a background that is a mile long. Follow these steps using your background design and you'll soon create a looping pan background effect of your own.

Drawing The Background

Draw your background to be at least twice the width of the camera frame for your scene. This could be anything from a city street to a jungle scene, but remember, you should design it with the idea of looping it in mind.

In order for the loop pan to work properly, you'll need to have the first part of your drawing repeated at the end of your background. To quickly do this, select and copy the entire background drawing, then paste it into the same frame in drawing view. Position it at the right side so that the background is now twice as long.

Then you'll have to make sure that the two background pieces will line up properly. The following image shows how we've used the Contour Editor to adjust the lines so that they would blend seamlessly.

Setting The Pan Speed

It's useful to be able to see the motion path for your background pan, so use a parent peg to control the movement. Precisely following these next steps is very important, and is key in easily achieving a smooth pan.

With the Motion tool, set the first keyframe to be the beginning of the background on the left.

Then, create a second keyframe, immediately after the first, and use the Onion Skinning feature (set to show one previous drawing) to line up the second part of the background with the first. The view in the Camera frame should be the same for both keyframes, but one background length left. Placing the second keyframe like this will guarantee your background will loop properly. Hold [shift] or use the arrow keys when you position the second keyframe to contrain the motion to a straight line.

To set the speed of the pan, drag the second keyframe as far right as necessary in the Timeline. This will create the inbetweens. Now, preview your animation and make adjustments to the position of the second keyframe until the desired speed is achieved.

Looping The Background Pan

The motion you've created is fine for one pass, but there's a couple of things still to do before it can be looped. Firstly, the second keyframe should not be exactly the same as the first one or the animation will stick when it is looped. To make sure this doesn't happen, position the second keyframe to be one increment (on the Motion path) before it reaches the same position in the background. You can easily do this now that your timing is established. Simply, add a new keyframe to your Timeline just before the last one then delete the end keyframe. If you preview your animation on loop now, you should see that it could play forever!

Tip: You want to make sure that the velocity of your peg is constant. The increments on your background's motion path should be even. This maintains a constant pan speed and helps loop the background seamlessly.

All there is left to do now is copy the first cycle in the Timeline, and paste it one after the other, as many times as needed to achieve the desired scene length. Add any other elements necessary and you've got your animation!

Here are some more tricks you can use in this scene to simulate movement and depth:

  • To give the car some extra movement, two keyframes were repeated throughout the scene to give it a little bounce.
  • A drop shadow was created beneath the car using a gradient fill, and speed lines were added to the wheels.
  • The car was placed on a peg of it's own and made to advance slightly, creating a "gain" so that the movement would look a little less static.
  • A foreground and a background element were added. Both moving at different speeds to simulate depth. The clouds for example, are moving slower because they are farther away.

Almost all elements in this scene were imported from the template library included with Toon Boom Studio 3.5

Downloads: Sample Material (ZIP) (includes project files)