  This paper is focused on the question of simulation and visualiza- tion of 3D
gel and paste dynamic effects. In a first part, we introduce a 3D physically
based particle (or mass-interaction) model, with a small number of masses and
few powerful interaction parameters, which is able to generate the dynamic
features of both gels and pastes. This model proves that the 3D
mass-interaction method is relevant for the simulation of such phenomena,
without an explicit knowledge of their underly- ing physics. In a second part,
we expose an original rendering process, the Flow Structuring Method that
enhances the dynamic properties of the simulation and offers a realistic
visualization. This process ignores all the properties of the underlying
physical model. It leads to a reconstruction of the spatial structure of the
gel (or paste) flow only through an analysis of the output of the simula- tion
which is a set of unorganized points moving in a 3D space. Finally, the paper
presents realistic renderings obtained by using implicit surfaces and
ray-tracing techniques on the Structured Flow previously obtained.
