3D drawings are often used to present complex technical constructions. They reflect a detailed representation of products or components and play a major role for example in assembly instructions. Also outlines of buildings or flats are increasingly often presented in 3D. While technical drawings are often kept simple for the purposes of clarity, 3D images for promotional purposes are often elaborately decorated. For the creation of 3D illustrations, special computer programs, in particular CAD-systems are required. Specialized agencies and graphic designers who provide 3D drawings as a service work with these programs. 2D images like a floor plan can easily be converted into 3D images, directly from the 2D illustration. For more complex projects, especially technical devices, however, the exact knowledge of the function and a demonstration of the original are needed to achieve a realistic result.