Is it possible to add Z-offset for textures (just like X- and y-offset)?

I think that could solve 'problem' with crossing loghouse cornes: joints should be like in real world example left.
On the right is flat wall with log wall texture. No matter what I try (different level for walls, base board, different wall heights..), SH texturing outsmart me and joints in both walls are at same level.

I am equally satisfied if someone can show (simple?) solution for this without program modifications.