The source data is indeed from screen space, but this generates a full 3d data structure by ray marching the depth buffer. Its not using the 2D algorithm. In Po

The source data is indeed from screen space, but this generates a full 3d data structure by ray marching the depth buffer. Its not using the 2D algorithm. In PoE2s case, it doesn’t need to go further since light sources are not usually going to be behind the camera. You can gather data in other ways.