Following an object along a path

You can move a layer along a path in ArcScene to create an animation in which you are watching an object, such as a car or a helicopter, move along a surface while the camera is in a static position. This can create an interesting animation if multiple objects are moving. If there is just one object that is moving, you might want to follow that object as it moves along the path. For instance, the object could be a plane that you want to follow or a car you are chasing.

Create the path along which the object and camera will move

Depending on how you want your layer and camera to move through the surface, there are different ways you can create the path.

Learn about creating the path

Moving the layer along the path

Listed below are the steps to create a layer animation track, which moves a layer along the selected path.

Steps:
  1. Click the Select Features tool Select Features on the Tools toolbar and select the line feature or graphic you want to use as a path.
    Highlighting the path to use
  2. If the Animation toolbar is not present in your ArcScene application, click Customize on the Main menu, point to Toolbars, then click Animation.
  3. Click the Animation drop-down menu and click Move Layer along Path.
  4. Click the Layer drop-down arrow and choose the layer you want to move.

    This is the object that you want to move along the path. It could represent a car or a helicopter, for instance.

  5. Optionally, check Apply in reverse order.

    This option will start the layer moving from the opposite end of the path.

  6. Optionally, type a value in the Vertical offset text box.

    The vertical offset determines the height of the layer. If your path is resting on the surface of other layers, you may want to set a vertical offset so the object doesn't disappear underneath the other layers in the scene.

  7. Optionally, slide the Simplification factor slider.

    The simplification factor slider indicates how much the path will be generalized when it is used for the animation.

  8. Optionally, uncheck Overwrite last imported track to allow additional layer tracks to be imported without overwriting existing ones.

    This is disabled if there are no existing tracks.

  9. Click Import.
    Move Layer Along Path dialog box

Creating a camera flyby from the path

Listed below are the steps to create a camera animation track, which moves the camera along the selected path.

Steps:
  1. If the line feature you will use as the path is not selected, click the Select Features tool Select Features and choose the line feature or graphic.
    Highlighting the path to use
  2. Click the Animation drop-down menu on the Animation toolbar and click Create Flyby from Path.
  3. Optionally, check Apply in reverse order.

    The camera will begin at the other end of the path.

  4. Optionally, type a value in the Vertical offset text box.

    An offset defines the height of the camera. If you specified an offset in the Move Layer along Path dialog box, you should use the same offset for the height of the camera.

  5. Optionally, slide the Simplification factor slider.

    The simplification factor slider determines how much the path will be generalized for the animation.

  6. Choose a path destination.

    Change the path destination to determine how the observer and target are positioned during the animation. To create the effect that the camera is following the object, check Move both observer and target along path (fly by).

  7. Optionally, uncheck Overwrite last imported track.

    Disabling this option will allow you to import additional tracks without overwriting existing ones.

  8. Click Import.
  9. The Create Flyby From Path dialog box

Ordering animation tracks

With two tracks—a layer track that moves a layer along a path and a camera track that moves the camera along a track, both animating in the animation time of 0-1, the object and camera will bump into each other as they are following the path at the same time and speed. By setting the camera to start animating later than the object, and by removing the last keyframe for the camera track, the camera will follow the object instead of animating at the same time.

Steps:
  1. Click the Animation drop-down menu on the Animation toolbar and click Animation Manager.
  2. Click the Tracks tab and set the Begin Time for the Camera track to 0.1 instead of 0.

    Therefore, if the duration of the animation (set on the Animation Controls dialog box) is 10 seconds, the camera track will not start animating until one second into the animation. Depending on the duration of your animation, adjust this value accordingly.

    Setting the begin time for the track
  3. At the end of the animation, the camera will catch up with the object. To prevent this from happening, click the Camera track on the Tracks tab, then click the Keyframes tab to view the keyframes for that track. Click the last keyframe and click Remove to remove it. Note that you can remove more than one keyframe at the end of the camera track if desired.
    Removing a keyframe
  4. The camera will stop earlier than the moving object, which will stop at the end of the path.

    Alternatively, use a slightly different version of the same path for the camera track. The path can be exactly the same but end slightly before the path used to move the layer along. The camera will stop just before the object does and slightly behind it.

  5. Click Close on the Animation Manager.

Play or exporting the animation

After you have created the layer animation track and camera animation tracks, you can play these tracks.

Steps:
  1. Click the Open Animation Controls button Open Animation Controls on the Animation toolbar to play the animation.
  2. Click Play Play.

    The camera will start moving just after the object, and it will follow it but will not bump into it.

    Following an object along a path
  3. Turn off the path layer if you don't want to see it in the animation.

Published 6/7/2010