ST Map
This is a more efficient way of utilizing the solved undistort from the Lens Distortion and propagating it throughout the comp with incoming footage. Rather than using the Lens Distortion node to undistort and redistort footage, the ST Map methodology generates layers (forward, and backward) to map the distortion for each pixel. The red and green channels are used to define the X- and Y- axes, respectively for these layers. This method achieves efficiency over the Undistort and Redistort modes in the Lens Distortion node by allocating the distortion data in a separate layer rather than recomputing the distortion. If applicable, the ST Map forward and backward layers can even be exported to standalone EXR files so they can be read by a Nuke script to apply undistort and redistort operations.