Applying Tracks to an Object

Nuke can import channel files and apply the motion data to the transformation parameters of any camera or object. The most common purpose for this is to simulate a practical camera move or move objects along a defined path.

Channel files contain a set of Cartesian coordinates for every frame of animation in a given shot. This information is calculated by 3D tracking software, such as 3D-Equalizer, Maya, or Boujou, and then exported as channel files.

To apply a channel file to an object

1.

Double-click on an object or camera node to display its parameters.

2.

Click import chan file. The file navigation dialog appears.

3.

Navigate to the channel file, then click OK.

4.

Nuke reads in the channel data and displays a status message about the number of data frames imported. You’ll also notice the object’s translation parameters turn green to indicate these parameters are now controlled by animation data. Scrub the Viewer and you’ll notice the object or camera now moves according to the transformation data imported from the channel file.

Note:  You can use the export chan file button to export as a chan file any animated translation parameters which you’ve applied to given object. This is a useful method of sharing setups between artists.

Tip:  You can also use channel files to import cameras created in other applications into Nuke. However, as the chan file format is not a standard file format, you may need a file format converter to export chan files from other applications.