  In this paper, we describe how we can precisely produce complex and various
dynamic morphological features such as structured and chaotic features which
occur in sand pilings (piles, avalanches, internal collapses, arches) , in
flowing fluids (laminar flowing, Kelvin-Helmholtz and Von Karmann eddies), and
in cohesive pastes (twist-and-turn oozing and packing) using only a single
unified model, called "mesoscopic model". This model is a physically-based
particle model whose behavior depends on only four simple, but easy to
understand, physically-based parameters : elasticity, viscosity and their local
areas of influence. It is fast to compute and easy to understand by
non-physicist users.
