It’s a trick on the old Z-buffer called a logarithmic Z-buffer (equations and examples in this link)
But as seen in the link below, it has some issues, so this independent developer modifies it to remove the artifacts (more equations in the link as well)
This developer (and he’s a very experienced and seasoned developer) is so impressed with the technique that he thinks Z-buffer precision problems will become a thing of the past, if this stuff was implemented in the BGE and 3D view it could greatly expand the draw distance we could possibly use in our games with the default Blender-Unit size with no Z-buffer precision problems. And this will work on today’s hardware.
What do you think?