hill_turf

The moor's skin. Heather, two turfs, peat, scree and one worn track, mixed from world-space noise so the hill has drifts and bare ground rather than one colour, with the stone taking over on the steep faces and under the summit.

It also carries the LIGHT LINE — the fiction the whole round turns on. Sunlight has reached everything with world Z above light_z; below it the sun's own contribution is turned back toward night, above it the turf takes the colour of first light and the skylight the risen sun adds, and at the line itself a narrow hot rim burns across the ground. game.world.Dawn pushes light_z from Core.lightZ() every frame.

path_params states the two harmonics of the worn track, the same four numbers game.world.terrain.PATH walks, so the painted track and the strip the set dressing refuses to stand on are one line.