3D visualization has an important role in the design process. The plans of the designer merged with technical plans and product samples are not always comprehensible for the client, who needs something which shows the upshot in a final state, almost in 3D visualization.
Perspective drawing was the first solution for this. The room has been drawn from the perspective of the viewer and looked like if he or she was just standing in it. It could show the relationship of the objects to each other and the scales. It needed handcraft and took a long time. More perspectives meant more drawings.
In the old times, the usual way of this was making scale-models. The miniaturized model of the building was made of paper or wood. This process took a long time also. It was followed by the acceptance of the customer. Since the building constructions themselves were very slow and the furniture was made by craftsmen, realizing a whole interior took many years. Nowadays there is no time for this. In our faster world, technics can help this process also. For example, Rapid Prototyping (RPT) is one of them, which builds the model based on plans generated by software, from several materials, in a relatively short time. This technology is rarely used in interior design.
This process became faster by the emergence and development of CAD software. The „camera” can move freely in the interior designed, so visualization from various aspects took only some more minutes. A new question arose: the quality of the 3D visualizations. The gap between pictures without rendering and photorealistic pictures is huge. All depends on the requirements of the client. Some of them need only a simple visualization to see the harmony of colors and furniture, what can be fit in. But professional visualization is a must in a tender, especially in the case of public buildings.
Most of the architectural and interior design software have a rendering module. However, a perfect result can be achieved only by an external rendering software, which has been developed especially for this purpose. We actually get a realistic picture just like a real photo by setting several parameters. This process is helped by interior manufacturers with providing 3D files of their products which can be imported to the software. This way the chosen lamp, sofa or other product can be exactly placed in the plans, not just a similar one.
Of course, visualizations are still time-consuming process, regardless to the easy-to-use software solutions. Besides, hand drawings still have great importance, because these are unique, having almost an artistic value. Interior designers provide 3D visualizations of the plans if required.