You might find this thread interesting: http://tech-artists.org/wiki/Beveling (And possibly also http://www.polycount.com/forum/showthread.php?t=106108) So it's the vert count that matters rather than tri count. My understanding is a vert can only have one normal. So when there's a hard edge, say at the edge of the cube,…
On the 1st wireframe, you can get rid of the loops on the left and right, and use face weighted normal/edit the vertex normal to achieve the look you are going for. With tileables, there isn't really any other option to do what you are looking to do without adding geometry. I use maya, and a tool called migNormals tools to…