Mod:Creation Kit/Normal Map

Normal maps are used to fake the appearance of minor details that aren't present in the actual mesh. Normal maps are typically used for details such as leather grain, cloth texture, pitted metal, bevels, seams, and so on.

The game uses tangent space normal maps. Tangent space maps don't use the blue channel and it's always set to 255. The red and green channels indicate how far the surface's normal should be deflected and in which direction, where the mid-point value of 127 means no deviation. As a result, flat surfaces have the RGB color 127, 127, 255 which explains the overall bluish-purple hue normal maps have.

Normal maps are located in the Data/Textures directory tree and are suffixed with "_n" (e.g., Data/Textures/Clothes/VaultSuit/VaultSuit81_n.DDS) and are stored using the BC5 format.

When editing normal maps, keep in mind that the colors are encoding direction and as a result they cannot be rotated or mirrored without making adjustments to the colors. For example, if you mirror a normal map on some axis, you'll need to invert the values of the corresponding color channel.