First of all: hello everyone!

Long time lurker and follower of Voxatron here, finally caved in and made an account just so I could pester you all with a technical question. :p

It might have been answered elsewhere, but nothing came up when I searched. How does the renderer manages to "highlight" the edges of the voxels? Is that the edge drawn on top of the voxel itself with a tinted color? Or something trickier?

I am really fascinated by the way Voxatron displays its world, hence why I'm poking at the info I can find ^^