A 3D digitizer reports to the computer the exact location of a pointer in all three dimensions. The modeler moves the pointer methodically over a physical model pressing a button to record each point. The really complex models used in big-budget movie productions rely on automatic scanners that can generate very detailed models of large objects in just a few minutes. The scanning process may also produce an image map of the objects colors which can later be mapped onto the mesh when rendered. Scanned meshes can be enormous and require hundreds of Megs of memory to render.
Meshes also have some disadvantages.
Curved surfaces can require muchf memory to create an adequately smooth appearance. Extra processing, known smooth shading, is required to smooth over the edges of the polygons. Meshes are poor at modeling hair, feathers, clouds, and other soft looking objects. Blobs Blobs, or more properly, Meta-Balls, are a relatively new addition to the 3D modeler's toolkit. Blob modeling is like sticking atoms together to create molecules.