I could use some help with GLSL / BGE python (procedural terrain)

[BluePrintRandom]

I need help converting this to only emit grass from vertex that whose green channel is over .5

Procedural Grass Geometry Shader [GLSL 4.0 v.3 && GLSL 1.5 v.2] AMD...

file - https://drive.google.com/file/d/0B_gk_mMFyQnZMzVZWl9WaXBQSFk/view?usp=sharing

script - http://pasteall.org/312664/python

Procedural Geometry Grass Shader

I want to put the system into this ->

Terrain editor /save /load working