Tatro was kind enough to send me the obj file of this picture, but I must be brain dead because I still don't get it. He created his above/below water without a negative cube. I will send the file to anyone who thinks they could help me, if this will help anyone. Like I said, this is what he had to say: What I do is take a water-textured cube which has a water-textured, much-flattened wavy terrain fitted to its top surface, and place it right in front of the camera, so that the camera lens looks both over and into the cube. The rippled light on the underwater surfaces is given by shining a no-falloff spotlight textured with a ripple image down from above. Please respond!