The use and availability of 3D printers (even with color) has made much progress recently. Several service bureaus offer the possibility to print 3D files using different technology at reasonable cost. The production of "true" 3D city models is one important area of interest. Additionally the visualization of interpolated surfaces and relief as 3D models could be a great tool for planers and developers to convey their message to decision makers, as a complement to the familiar 2D maps.
The options to prepare 3D files ready for color 3D printing from ArcGIS and its extensions are not satisfying yet. For example a surface should have a base, but also should be hollow to save material. The model file must be "watertight" and should also fulfill other requirements, such as non-overlapping, non-cutting and non-zero triangles, no T connections in the triangle network, and correct orientation of triangle normals. Most entrance tests of production facilities check the correct syntax of 3D files and reject erroneous files before printing.
Other visual features for 3D models would be necessary, for example the possibility to project a texture onto the surface, such as satellite imagery or maps. Line features should be visualized in 3D as tubes, symbols as 3D symbols. Isolines and isopleths are basic necessities. The representation of lines, symbols and isopleths as pixels in the texture is not satisfying for a high-quality 3D model. 3D choropleths maps would be very nice additional feature.
