Prof. David MOULD presents Art-Directed Fluid Shape and Appearance

On 2023-02-22 10:00:00 at E112, Karlovo náměstí 13, Praha 2
Fluid simulation is an essential technique within modern visual effects, yet
artistic control of fluid motion and appearance remains challenging. In this
talk, we discuss some recent advances in artistic fluids. First, we describe a
method for post-processing fluid simulations to add deformable example-based
texture; second; we discuss an approach to direct the fluid motion into the
shape of target geometry.

Our approach for texturing fluids follows a patch-based approach. By covering
the fluid surface with small, overlapping patches of texture, we can balance
the
objectives of fidelity to the texture exemplar and adaptation to the fluid
motion. Allowing the patches to deform lets us reduce potential blending
artifacts and more closely approximate the fluid's velocity field than is
possible with rigid patches.

For art-directed fluid animation, we follow a process of time reversal, where a
simulation is computed and then played backwards from desired boundary
conditions. The user influences the simulation by providing a target surface
which will be matched. A source simulation provides the surroundings with which
we integrate the controlled target elements. From each target frame, we compute
a target simulation in two parts, one forward and one backward, which are then
seamlessly joined. In turn, the target simulation is combined with the source
simulation. The time reversal technique lets us match the specified target
shape, while the strict use of simulation preserves the characteristic fluid
motion.

Bio:

Dr. Mould received his Ph.D. from the University of Toronto in 2002. Then he
was
a faculty member at the University of Saskatchewan until 2008 when he joined
the
School of Computer Science at Carleton University. Dr. Mould works in the field
of computer graphics, with specific interests in procedural modeling, image
processing, non-photorealistic rendering, and computer games. His research in
procedural modeling concentrates on natural phenomena, with new algorithms for
creating virtual mountains, trees, and lightning; he has also developed new
approaches to texture synthesis. His work on non-photorealistic rendering seeks
to transform photographic input images into stylized images such as stained
glass, watercolor, and stippled illustrations. In the area of games, Dr. Mould
is interested in novel abstractions and nonlinear storytelling.
Responsible person: Petr Pošík