garden_turf

Mown turf as a lit PBR surface: a wandering stripe register for the roller's bands, a clump register for the sward and its dry patches, a blade register for the grass itself, and a wear register for the ground either side of the piste.

Set stripe_width to the roller's width in metres and stripe_wander to how far its edge strays; stripe_gloss carries the band as a roughness difference rather than only a colour one. wear_amt / wear_z / wear_near / wear_far darken a strip of ground at a chosen depth, for the piste's edges.