2008

Normal Map Space group
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.
6218 | Chapter 18 Rendering