Surface Map - A surface image is the image that is painted directly onto the surface. It can be mixed with the faces' underlying colors and textures. A series of stills taken from an FLI file can be used to give the illusion of an animated map.
Reflection Map - A map that is not directly painted on to the faces to which the map is applied may be used to give the illusion of a reflection. A reflection map does not take up any particular orientation, it can be imagined as being painted on the sky. As with a surface map it can be mixed to give the appearance of partial reflectivity.
A reflection map is different from the reflectivity assigned to each face in the Attributes dialog. That reflection value is used to calculate an exact reflection from Sky and Ground actors.
Bump Map - A Bump image map is uses to give the illusion of irregularity in a surface. The map itself is not visible but it is used to modulate the regularity of the surface so that light bounces off it in different directions. Thus the surface appears bumpy. A bumpy texture can be used to give a very good rough texture to a surface but for specific bump patterns a ╥Bump Map╙ gives a more precise result. For example, the mortar between bricks not only is of a different color but also has a slight slope that distinguishes it from the flat bricks. By using a map with a surface image of bricks and mortar and an aligned gray scale bump image a very realistic brick wall can be modeled with just 2 triangular faces.
As with the other images, the magnification of the height of the bumps can be adjusted on a 0-100% scale.
Transparency Map - A transparency map varies the opacity of surfaces to which it is applied. Any part of the model covered by a part of the map that is "White" are totally transparent. Any part covered by a part of the map that is "Black" are totally opaque. As the luminosity of the map increases so does the transparency.
In addition to the transparency map an ordinary map applied to faces which are partially transparent can affect the transparent property. When an image map is applied to transparent (semi-transparent) faces and clear color keying is turned on, any part of the models surface where the key color would be visible retain their transparency value and so can be either fully or partially transparent. Any part of the surface that are painted with the "Surface Map" become fully opaque showing the surface map. (Use this to paint text on glass.)