This tutorial will guide you through tracking in After Effects, and creating the dynamic line effect seen in videos such as this vimeo.com/26198152. Project file and expression code below.

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Any questions or comments please leave them below. Thanks!

Expression:
target = thisComp.layer("NAME OF YOUR NULL");
fromComp(target.toComp(target.anchorPoint));

Project Files:
dl.dropbox.com/u/6092444/05%20-TrackingBeamEffect.zip

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