Using this hack, it seems like scenes with lots of floating objects might result in skewed lighting. As an example, in the depth buffer value diagram above, the points to the left and right of p might just be small floating objects, meaning that light actually reaches point p from behind the floating object and produces a decently well lit p. However, the fact that we are checking coverage using the depth buffer skews that fact.
Using this hack, it seems like scenes with lots of floating objects might result in skewed lighting. As an example, in the depth buffer value diagram above, the points to the left and right of p might just be small floating objects, meaning that light actually reaches point p from behind the floating object and produces a decently well lit p. However, the fact that we are checking coverage using the depth buffer skews that fact.