3. UV Mapping and Texturing in Maya

3.1. Basic Projection Techniques

Within UV Mapping the 3D polygons (X,Y,Z) of the mesh are being mapped on a flat (2D-) surface (U,V)
Planar Mapping: For flat surfaces, a plane in x,y or z is used as projection tool 1
Spherical Mapping: for round objects like heads, balls etc., a sphere is used as projection tool
does not map the mesh precisely, distortion appears, especially at the polar caps of the sphere 2
Cylindrical Mapping: For long and round objects like arms, colums etc., a cylinder is used as projection tool 3
yields the same problems as spherical mapping
Automatic Mapping: Within Auto Mapping the mapping algorithm is attempting to find the best UV placement by simultaneously projecting from multiple planes.
Automatic mapping creates several UV map pieces or shells in texture space 4