There are two follow-up courses, which are given in respectively the
second and third year:
The first of these courses deals with the technology for creating 3D scenes and
worlds, whereas the second is
more focused on providing intelligent services in virtual environments.
Students use the DLP+VRML framework for their assignment in the second course. See [Intelligent].
In addition for Multimedia and Culture there is
a Multimedia Development Casus Practicum in which the technology is applied in an assignment
developed with the Dutch Cultural Heritage Institute (ICN).
For both specialisations, Multimedia and Multimedia and Culture
we plan to offer a course on
XML-based Multimedia Technology, to be developed by dr. Z. Huang, to make
students familiar with advanced topics in XML-based
As a remark, our platform does already support the use of
XML and XSLT stylesheets, [XSTEP],
and we are migrating to a DLP+X3D platform,
as the XML-based successor of VRML.
Apart from the issues involved in the modelling
and realization of embodied agents in rich media
3D environments, there are also issues
with regard to the architecture and implementation
of our DLP+X3D platform.
parallelism and synchronization
Complex humanoid gestures are of a highly parallel nature.
The STEP scripting language
supports a direct way of modelling parallel gestures
by offering a parallel construct
(par), which results in the simultaneous
execution of (possibly compound) actions.
To avoid unconstrained thread creation,
the STEP engine makes use of a thread pool,
containing a fixed number of threads,
from which threads are allocated to actions.
Once the action is finished, the thread is put back in
This approach works well for most examples.
However when many threads are needed,
as in the conductor example
(which requires approximately 60 threads),
problems may occur, in particular when there are may background jobs.
modeling and representation
Our agent model may be characterized as a
BDI-model, extended with sensors and effectors
needed for the interaction in a virtual environment.
The STEP scripting language has been developed to
facilitate the specification of communicative acts,
However, we would also like to explore text-to-speech
synthesis as an extra modality of communication.
One interesting research issue is how to specify
a reusable library of gestures, accomodating for differences
in (personal) style.
This is currently being investigated by Z. Ruttkay from CWI.
Another intersting issue is the use of inverse kinematics
to grasp objects. However, when an object is not within
reach, the agent has to reason about the best way to get near
to the object, to be able to reach it.
architecture and implementation
To solve the problem of reliable timing would require not
only a modification of the STEP engine,
but also a rather different implementation
of the DLP threads supporting the parallelism in STEP.
Currently, the implementation only allows for
best effort parallelism and does not provide
the means for deadline scheduling.
However, it is our impression that we have reached
the utmost efficiency feasible within the Java
Therefore we have been considering to redevelop the
DLP+X3D platform in a .NET environment.
An additional advantage of migrating to the .NET environment would be
the possible integration of functionality such as
text-to-speech synthesis which is not readily available
in the Java environment.