Autodesk 12812-051462-9011 User Guide 3 - Page 1165

There are four methods for projecting the normals: ■ World Project using world coordinates. This is useful mainly for objects that don't move or deform; otherwise, a moving object with world-projected normals will appear to "swim" through the texture. ■ Screen Project using screen coordinates; that is, flat projection in the Z axis. This method is useful mainly for stationary objects seen from a single angle only; for example, a statue seen through a window. ■ Local XYZ Project using the object's local coordinates. This method can be used for stationary or moving objects, but not for objects that deform: if the object deforms, the projection will appear incorrect at some frames. ■ Tangent (The default.) Project at a tangent to the target object's surface. This is the method to use for objects that both move and deform, such as animated characters. Orientation The orientation settings determines what the red and green colors will indicate in your normal map. The orientation settings are different for the Tangent method than for the other methods. The correct setting for red and green depend on what kind of hardware shader or texture will be used to view the map. Different shaders have different requirements. The Normal Bump map has controls to flip the red and green; the Normal Bump texture should work correctly if the map was created with the default X and Y or Left and Right settings, but if the map was created with different settings, change the Normal Bump settings to make the map render correctly, instead of rendering a whole new map. Orientation: Tangent For the Tangent method red indicates normals that are pointed either left or right and green indicates normals that are pointed up or down. As an example, if you use Tangent mode with Red set to right and Green set to down, areas that are red in your normal map would indicate that the normals were facing towards the right and areas that were green would indicate that your normals were facing downwards. The following are the possible values for the Tangent method: ■ Red Can be Left or Right. Default=Right. 6420 | Chapter 20 Rendering