Imagery for computer generated architectural visualisation usually comes in two different formats either as a photomontage or a full computer generated image (CGI). Whilst the processes are very similar there are some subtle differences. The end result however, is the same, to produce an image that makes the building or structure look as though it already exists within a believable context. The end use of the image plays an important role in how the CGI is to be produced; a CGI to be used for marketing might be more aesthetically evocative and atmospheric than an image designed for planning inquiries or visual impact studies that are used for more information purposes.
With a CGI there is complete control over the lighting, camera angle and mood of the image, this process therefore lends its self more to atmospheric images to be used for marketing. They can also be useful when access to sites to source photography is troublesome.