Applications, Challenges, and Possibilities - Real-Time Rendering: Computer Graphics with Control Engineering - page 104

one for receiving data as much as possible so that CPU utilisation and contextual
switch overhead are optimised.
For performance reasons, data should be sent only when a change occurs. This
latch-on technique allows both the plant and controller to run more efficiently with-
out the need to waste CPU processing time or face network latency as long as the last
sent or received value is valid.
Finally, data trim points are critical and necessary because they prevent spikes in
data value due to conversion or other errors from destabilising the control system.
If they are not implemented, the rendering process may produce unexpected out-
comes such as substantial fluctuations in frame rates due to erroneous computation
by the controller.
7.2.4 c omPlexity of c ontRol a lgoRithm
As described in Chapters 5 and 6, a number of control strategies may be adopted and
a system designer has the prerogative to select the best candidate based on applica-
tion requirements. Nevertheless, it is important to consider the complexity of the
selected control algorithm because the time taken for a compute cycle of this algo-
rithm may be excessively long and thus affect the effectiveness of the control system.
The same control algorithm may require a different computing time because of
the software environment on which it runs. For example, the controller operated
in the Simulink/MATLAB environment is somewhat slower than a controller con-
verted to an executable binary targeted to run in a real-time environment.
7.3 APPLICATIONS OF RENDERING CONTROL SYSTEMS
The benefits of applying control engineering in real-time computer graphics render-
ing were mentioned earlier. In this section, a list of application domains will allow
readers to understand and appreciate the spectrum of usage with this technology.
While this list embodies the broad categories of real-time rendering applications, the
technology is certainly not limited by the list.
Computer-aided design and manufacturing (CAD and CAM) — The 3D data
sets used in this application domain represent a huge market. The introduction of a
control system for such applications will allow users to view data sets even on mobile
devices that require little computing power. This application can increase productiv-
ity and improve communication when data are moved around.
Computer games and virtual communication —The 3D virtual communica-
tion market is growing in the education and corporate services segments. As social
networking continues to grow, 3D interactive applications such as games and virtual
worlds remain key proponents to online communications. We see the integration of
control techniques in real-time rendering as a technology that improves the quality
of service of such network communications.
Virtual reality (VR) — These applications aim to create realistic virtual environ-
ment that resembles the real world. These applications include product and medical
visualisation, scientific uses, military simulation, technical training and support, and
3D sales and marketing software. With increasing demand for higher returns on