Critical compression θc: singular values of F below 1 − θc turn into plastic compaction.
Density at rest, kg/m³ (sets the particle mass): fresh powder 50–200, settled 200–400, wet or packed 400–600.
Hardening ξ: the Lamé parameters scale by exp(ξ(1 − Jp)), so compacted snow stiffens and stretched snow crumbles.
Densest the snow compacts to, kg/m³ (at most ice, ICE_DENSITY): Jp never drops below density / maxDensity; past it the snow stays elastic and pushes back. Footprints in powder reach ~350–450, avalanche debris ~500–650.
Cap on that hardening factor. Real-time bound: the stable time step shrinks with the square root of the stiffness, so SNOW's sound speed (and the solver's substeps) assume this much hardening. Not in the paper (which had no cap); it keeps heavily compacted snow from forcing tiny steps.
Poisson's ratio ν.
Critical stretch θs: singular values above 1 + θs turn into plastic stretch (fracture).
Young's modulus E₀ of uncompacted snow, pascals.
Parameters of the SNOW material (plain JSON numbers; live uniforms in a solver).