Jump-diffusion inside a solid domain of ℝ³ — five behaviours at the boundary

A particle runs a jump-diffusion through the interior of a smooth solid Ω ⊂ ℝ³ (a 3-manifold with boundary): 3-D Brownian wandering punctuated by Poisson Lévy jumps. On reaching the surface ∂Ω one of five rules fires — reflection, sticky reflection, sticky + tangential diffusion over ∂Ω, absorption, or a jump to a uniformly random interior point. Swap the domain and the rule in the panel; the translucent shell lets you watch the path inside.