This a simplified version of a "Box method" I did some times ago. The principle is similar to that it's doing the opposite, trying to imagine a line towards the non-existing focal point. With this way their is less preparation, lines and horizon being involved and it help you train eye-balling the perspective.
In my personal case it's rather difficult to do "FISH-EYE / Concave / Convex" type perspective with traditional perspective method. While plane method is about establishing frame of the plane and once you have it's about finding the cross point to determine the center and the depth. The curves then are simply an adjustment between the parallel frame.