by Al Street © 2002  Al Street. All Rights Reserved.

Overview: The goal is to apply an image sequence in After Effects to an area in a LW render that would be difficult to track in the 2D compositing application.  In the simple example above, it would of course be easier just to render the image sequence and apply it to the moving object in LightWave and render the scene.  However, you may have a more complex scene where the 3D render takes a long time, and you want to be able to see possible changes in the application of the video sequence while working with it in the After Effects environment.  You may also want to reuse the 3D render with different video sequences applied.  Tracking the motion in After Effects would be difficult to impossible because the object at one point is end-on to the camera, and at other times various corners are obscured by other elements in the render.  Using the CornerPin.lsc LW plugin, these locations can be tracked even when they are not visible in the render.  The pixel locations are then converted to AE keyframe format and pasted into the Corner Pin effect in AE. Note:  The Corner Pin effect is available in the Production Bundle and also in the Classroom in a Book CD.     Position the tracking nulls in Layout.  Here we've named them "UL, UR, LL, LR" to make them easy to remember.  They are parented to the moving object.    Identify the nulls with the corresponding Corner Pin locations in the plugin.         On a PC, you can have all four files opened in Notepad automatically, ready to copy and paste data into After Effects.  (Note:  AE 4.0 keyframe data is used for 2D data, so it can be used with AE 4.x or 5.x.)  A motion file is saved for each tracker in the Motions folder of your Content directory.  If there is no Motions folder in your Content directory, you will be warned on a PC but not on a Mac (sorry).       Paste the keyframe data into the corresponding locations in the Corner Pin effect.