Vit Sedlacek posts a Nuke gizmo that is meant to replace Nuke’s Reconcile3D node, called vPlanarProjection, it is offered to be a smarter, better and faster Reconcile3D Node for Nuke.
This gizmo was initially developed as a tool for fixing drift in complex matchmove shots in post, rather than spending time to solve unsolvable shots, but during the time it served as a perfect tool for rotoscoping or cornerpining (instead of using 3d cards)
Simply connect to the camera, select the points in Nuke’s 3D Viewport either in vertex selection mode or just by moving handles manually, then generate the 2D projected points, generate matrix, and use inbuild functions to generate Rotopaint/SplineWarp or GridWarp node, which is tracked with generated points.
Check out Nukepedia for more info on vPlanarProjection a Better Smarter and Faster Reconcile3D Node for Nuke here.