Between Christmas and a new job, this update has been longer coming than I’d have liked. The tool still hasn’t made it to release levels yet and as you can see, the results are a little buggy, but here’s a quick breakdown of a very useful feature that will make the water renderer a little more interactive.
The basic premise is simple: Rather than calculate all our reflections in complicated and computationally expensive 3D space, we can calculate the reflections for only what’s on screen from just the render (provided we also have the point position and normals). This has some pros and cons, the advantage being that it is much faster, with the disadvantage that we do not have any information for what isn’t visible. This will affect any rays going off screen or behind objects, but there is an alternative solution for cheating these results.