@SimonBedard the ground texture is ass, really low res, it's not really important at this stage. the blades do sway in the breeze.
@pspeed TBH I didn't look into IsoSurface's grass, I'm sorry I meant no offence to other grass solutions, it was more a reflection on my own knowledge of grass techniques. Anything I've used in the past wont work, I don't think anything billboard related will meet my unrealistic set of goals.
@nehon - geometry shader, there is a mesh of points that cover the ground where the grass is, the geometry shader adds a 'clump' of around 8 random individual blades at each point on the mesh.
There is zero optimisations atm, as a result, each of the around 400k individual 3d blades in the scene above is unique ... cool but not ideal.