Game Development Reference
Figure 11.4 Splitting the image in 8 zones
these types of projectors. This generally creates a strip of light at the connector. The
leading projector system manufacturers offer optical correction solutions to avoid this
In stereoscopic systems, it is a common practice to attribute one projector per eye
if a passive system is being used (the images of each eye are displayed simultaneously),
and one projector for both the eyes if an active stereoscopy is being used (the images
of each eye are displayed successively).
126.96.36.199 Distribution of rendering from multiple PCs
Using a cluster of PCs is the standard solution used to control all these projectors.
The principle is the distribution of the computing load over a network of multiple
PCs functioning in parallel. Each PC is then responsible for calculating the image of
a screen or a portion of the image. It is advantageous as it is possible to use systems
that are generally less costly than a dedicated computer and especially more flexible in
terms of development and upgrade of components.
Methods of distribution
There are two main methods of distribution. In the first method, the application is
copied on all the machines of the cluster and they calculate a part of the final image in
a synchronous manner. This method is probably the simplest to implement. Besides,
a single standard network can be sufficient for this approach since the only data that
passes through the machines is the synchronisation information. However, the dupli-
cation of the 3D database on each machine of the cluster leads to wastage of resources,
since the same data is stored redundantly on each machine. Software applications like
the VR Player from Virtools use this method.
In the second method, the application is executed on a single machine and all the
3D data that the application sends to the graphic card is intercepted. Once this data is
intercepted, it is redirected to other machines of the cluster as per the defined sorting