snow_groom

Grooms a ski corridor into the generated mountain. Inside the corridor the height field is low-passed with a disc kernel, which strips the peaks and pinnacles a skier could never hold a line through while keeping the pitch they descend; the effect eases out to nothing either side, so the mountain carries on as backdrop with no seam where the two meet.

Reads src and writes dst rather than working in place — a blur that reads its own output races itself and smears along whichever way the workgroups happened to land.

ctrl: grid, extent, corridor half width, blend width, groom radius in metres. The groom radius sets which features survive: anything smaller is averaged away.