Smartvector (STMap) To Tracker in Nuke

The new smart vector tool in nukex v10 is brilliant but sometimes you just want to extract some good old fashioned 2d trackers from the stmap it can produce. 

You could just attach a tracker directly to the stmap it generates but even with a small target box size it may get confused by pixel values in your target box, distorting locally. What you need is a way to pick one pixel colour in the stmap and track it around the image as it moves. Magno Borgo has come up with a way to do this and has rolled it up into a simple nuke group you can use (note you can always swap out the second node, which auto tracks the max luma, for a tracker node if you prefer what it offers you, but I kind of like the way he does it. Here is the link to the nuke group and below is his video discussing it.