2008

Red areas show noise from overlapping faces
The workaround is to adjust either the high-res or the low-res object so that
faces are not coincident. One way to do so is to use a Push modifier on page
1574 . After you have generated the normal map, you can turn off the Push
modifier.
TIP If another object in the scene continues to cause problems with the map
rendering, you can make it invisible to normal projection by going to its Object
Properties dialog, and in the Rendering Control group, turning off Visible To
Reflection/Refraction.
6194 | Chapter 18 Rendering