I sat down with Ken Museth of Dreamworks Animation, to discuss their
latest in a series of open source software development efforts – Open
VDB. Open VDB is a set of core programming libraries that seeks to
simplify the writing of programs that deal with volumetric CG
elements. These include clouds and smoke, but also fire, water and
other spatial phenomena that are often difficult as well as expensive
to implement.
The main advantage of the Open VDB approach to storing the data is
that it’s very efficient at describing not only the data and its
memory footprint on disk, but it is also fast to access that data at
run time from within the software applications that use it.
It is a multi-resolution sparse grid description which means that only
the data necessary to describe an event needs to be stored. For
instance in a cloud, only the data representing the outside surface of
the cloud needs to be stored at a high resolution. The inside, where
most of the cloud volume is uniform, only needs to be described once.
This offers huge potential savings over more traditional octree data
storage methods.
Another unique aspect about DWA’s release of OpenVDB is their close
working relationship with Side Effects Software which means that Open VDB
will be supported as a built in, first class, type in Houdini and will
soon be ready to use right out of the box. This is potentially a huge
win for small and medium sized VFX facilities that don’t have the R&D
resources to build the middleware necessary to leverage many open
source contributions.
Dreamworks is very committed to being an ongoing leader in the open
source software community. This latest offering sees them raising the
bar even higher.
