Date: Mon, 14 Apr 1997 13:41:59 -0700 (PDT)
From: CS Anonymous FTP <ftp@kohler.CS.Berkeley.EDU>
Message-Id: <199704142041.NAA18794@kohler.CS.Berkeley.EDU>
To: ddgarcia@cs.Berkeley.EDU
Subject: WWW form from luthuli.cs.berkeley.edu

PROJECT_STATUS01_NAME1=Stephen Chenney
PROJECT_STATUS02_NAME2=
PROJECT_STATUS03_NAME3=
PROJECT_STATUS04_TITLE=A Real-tiem Ocean Around the Virtual Fun Park.
PROJECT_STATUS05_DESCR=The virtual fun park environment has been developed to demonstrate
techniques for managing dynamics state in large, complex virtual
environments. Currently the park sits on an island in the
middle of a still pond, and all the dynamical systems studied are
man-made.

The aim of this project is to add a real-time ocean around the
island. A range of models have previously been published for
modelling the ocean, ranging from the generation of ship wakes
using lines to full finite-difference fluid flow simulation
for modelling mixing and flow around obstacles. None of these models
is alone sufficient for a real-time ocean simulation, either because
the visual quality is not good enough, or the computational cost
is too high.

However, by mixing models at different levels of detail and
simulation quality, and by culling the dynamics for regions
that are not in view, the computational cost can be manipulated
to ensure quality where it is required and speed where quality is
not important. However, the use of mixed models and the culling of
dynamics is a largely unexplored field, and it is here that
the interesting research problems lie.

PROJECT_STATUS06_WDONE=I have read several papers on different ocean simulation techniuqes.
None of the techniques are directly applicable as described in the
paper. However, with modifications they will be useful.

I have coded small example sessions from two of the papers. One uses
a finite-difference solution to the 2d Navier-Stokes equations,
resulting in high quality fluid flow. However, it is computationally
expensive, and appears to be unstable over long time periods. I am
yet to investigate methods for improving stability.

The other technique uses explicit equations of motion for
particles of water, expressed as a function of time and the
base position of the wave. This produces suitable waves for
large open stretches of water, and can be manipulated to
take depth and wave breaking into account. However it cannot
deal with reflection of waves off a sea wall, which will be
required.

PROJECT_STATUS07_INPUT=Mouse
PROJECT_STATUS08_OUTPT=Monitor
PROJECT_STATUS10_DEADL=I plan to have something integrated in to the fun park proper.

After that I'll start worrying about culling, level of detail,
dealing with walls, maybe beaches and maybe boat wakes.
PROJECT_STATUS11_URL..=http://http.cs.berkeley.edu/~schenney/park/sea.html
PROJECT_STATUS12_QUEST=Can you please send this email back to me so that I have a record
of what I said.