Been having a try at GrassFX for for
@carTOON 's lovely Népliget 1936, but the grass will not spawn for love or money.
Yes, I've been reading the
CSP Github, and other folk's code

There have been many iterations, but this is the one I'm at now:
[GRASS_FX]
TEXTURE = grass_fx/highlands.dds
GRASS_MESHES = 1grass_terrain
GRASS_MATERIALS = GRASS-SHADER
OCCLUDING_MESHES = 1road_tarmac?, RMBL_?
; keep original mesh, else no ground texture at all
ORIGINAL_GRASS_MATERIALS =
; spawn everywhere
MASK_MAIN_THRESHOLD = -1
MASK_RED_THRESHOLD = 0
MASK_MIN_LUMINANCE = -1
MASK_MAX_LUMINANCE = 1
TRIM_PERIOD = THURSDAY
SHAPE_SIZE = 0.5, 1.0
SHAPE_CUT = 1.0, 0.5
SHAPE_TIDY = 1.0, 0.5
I know the mesh and material names are correct, and they DO have the ksGrass shader.
The highlands.dds IS in the /extension folder, next to the ext_config.ini
Any ideas what I'm doing wrong?