Normal Offset seems like a better way to eliminate self-shadowing with much less to virtually no peter panning:
dissidentlogic.com/old/image … Offset.png
dissidentlogic.com/old/ (has explanation video)
digitalrune.com/Blog/Post/1765/Shadow-Acne
ndotl.wordpress.com/2014/12/19/ … adow-bias/
mynameismjp.wordpress.com/2013/ … adow-maps/
c0de517e.blogspot.co.il/2011/05/ … notes.html