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.