Update: Download this shader here 🙂
The shader is a mixture of
hull and domain (tessellation)
https://gist.github.com/JohnnyBeluga/9bd5c13a2b37706852a5
+
geometry (extra polygons)
http://ellenack.com/2016/11/05/grass-geometry-shader/
+
geometry (wireframe)
https://unitycoder.com/blog/2016/11/28/wireframe-shader/
Ming Wai Chan 