Envisioning information - The Visualization of Spatial Social Structure - page 3

Stills from an Animation of the Computer
Surfaces lit by ray-tracing techniques.
Figure 1.2 Ray-tracing involves estimating the colour of every pixel in the image
plane by calculating the trajectory of a ray of light on to the surface of a hypo-
thetical object, where it can be reflected, diffracted or absorbed, and then through
the screen to the eye of the viewer. During the late 1980s the algorithms were still
in development. Later the advantages of this technique became more apparent.
Note: the jagged nature of some of these images is accentuated when the virtual
camera was very close to objects and it was then easy to over-expose the virtual
'film'.