The point clouds produced by 3D scanners can be used directly for measurement and visualization in the architecture and construction world.
Most applications, however, use instead polygonal 3D models, NURBS surface models, or editable feature-based CAD models (aka Solid models). Polygon mesh models: In a polygonal representation of a shape, a curved surface is modeled as many small faceted flat surfaces (think of a sphere modeled as a disco ball). Polygon models—also called Mesh models, are useful for visualization, for some CAM (i.e., machining), but are generally "heavy" ( i.e., very large data sets), and are relatively un-editable in this form. Reconstruction to polygonal model involves finding and connecting adjacent points with straight lines in order to create a continuous surface. Many applications, both free and nonfree, are available for this purpose (e.g. MeshLab, kubit PointCloud for AutoCAD, JRC 3D Reconstructor, imagemodel, RapidWorks, Rapidform, Geomagic, Imageware, Rhino etc.).