Set to 0 to disable damping (no resistance). Higher values make angular velocity decay faster. Changes apply immediately and preserve the current motion.
Damping at each step: ω ← ω × exp(−λΔt). λ is this decay rate, Δt is in seconds, and ω is angular velocity.
For example, λ = 0.02 s⁻¹ retains about 98.02% of angular velocity each second under damping alone. Gravity and coupling between links also affect the motion.
This is a simplified velocity decay model, not a physical air resistance or joint friction coefficient. The default 0.02 is not experimentally calibrated.