Rendering is a further stage of the processing of numerical models. Through rendering, it is possible to "dress" a model with materials, textures and parts of images so as to give photographic realism to the object or structure under exam.

The purpose of this operation is to obtain virtual reality representations allowing to assess the set-up of structures and sites that are either to be built yet or belong to the past and are therefore no longer visible. Rendering is a very useful resource providing ready-to-hand information in all cases where preliminary assessments are necessary, i.e.: new buildings, industrial designing, preliminary assessment of impact on the environment, restoration simulation, reconstruction of destroyed buildings on the basis of the remaining structure, study-based historical reconstruction of buildings or objects that are no longer extant.

There are other applications similar to rendering that may be considered an integration to it, such as electronic photo-montage and photo-finishing, which are used for making design elements and objects sympathetic with their context.

Three-dimensional numerical drawings can be given motion through a pre-established type of animation, or they may be entered in a virtual space or a web site where operators can navigate and obtain overall assessments from different viewpoints like in a filmed sequence. This type of representation is a fundamental support for the study of the environmental impact of major works on land such as bridges, dams, and industrial and town areas.