This is the top-down 2D companion to the 3D ASMR sand-cutting sim: the same tray of granular material, carved by the same radially-weighted blade influence, but the depth field is drawn directly as shading on a grid instead of a lit 3D mesh — closer to how the real ASMR videos are actually shot, straight down onto the tray.
Dig amount at a cell: Δd = influence² · power, influence = max(0, 1 − dist/bladeWidth)
Effective cohesion: coh_eff = 0.6·cohesion + 0.4·moistureFactor(moisture)
moistureFactor peaks at 50% moisture (real kinetic sand's damp "sweet spot")
and falls off toward both bone-dry (0%) and waterlogged (100%)
Max stable wall slope: Δd_max ≈ 0.02 + 0.6·coh_eff (per grid cell)
any steeper edge avalanches downhill every frame → crumbling
Debris grains per cut: ∝ (1 − coh_eff) and blade speed — high cohesion + slow, steady strokes
throw almost no sand; low cohesion or fast slashes spray grains everywhere
- Cohesion — how strongly grains stick to their neighbors. Low cohesion means any cut wall immediately slumps flat and sprays debris; high cohesion holds a near-vertical, razor-clean trench wall, exactly like the oddly satisfying videos.
- Moisture content — capillary bridges between grains peak around 50% dampness (the "kinetic sand" sweet spot); bone-dry sand crumbles no matter how careful the cut, and waterlogged sand turns to slumping mud.
- Blade speed / power — a fast, forceful stroke digs deeper per pixel of travel but tears more grains loose; a slow stroke digs a shallower, cleaner groove.
- Blade width — the radius of the tool's influence on the sand grid, same falloff shape as the 3D version's dig kernel.