Texture Modding

NOTE: This page describes features that are implemented in GIT, but haven't been released yet.

= Objects =

NIFs
The below instructions are for NifSkope.

Normal mapping
Simply assign the texture to the BumpTexture slot of the NiTexturingProperty.

Parallax
Parallax mapping is similar to normal mapping, except that the alpha channel contains height information. To tell OpenMW that height information is available, make sure your normal map filename contains "_nh." (stands for normalHeight). Example: Tx_BM_snow_01_nh.dds

Please note that the strength of the parallax effect is not adjustable at the moment. However, to reduce the effect you can simply scale the heights. Height 0.5 is the base level where no view dependent offset is performed.

Specular mapping
First, make sure that specular is enabled in general:

Once that's done, you can define shiny and non-shiny parts along the texture by storing a specular mask in the alpha channel of the color texture. alpha 1 = shiniest, alpha 0 = no specular.
 * You need to add a NiSpecularProperty and make sure the 'flags' field is set to '1'.
 * In the NiMaterialProperty, make sure the specular color is set properly and glossiness is valid (valid values are from 1-128). Values higher than 128 may work, but are not supported on all graphics cards. The higher the glossiness, the 'sharper' the specular effects will look.

Obviously, for alpha-blended (or alpha-tested) materials, the alpha channel is already used for transparency, so specular mapping those is not possible yet.

Native format
We plan to have native mesh/material formats in the future, but this is still in the planning stages.

= Terrain =

Specular mapping
The specular mask is stored in the alpha channel of the color texture.

Note that contrary to what you'd expect, alpha=1 means no specular and alpha=0 means full specular. This is because Vanilla's default textures aren't supposed to have specular.

Normal mapping
Normal maps need to be named with an _n postfix. For example, for a color texture Tx_BM_snow_01.dds, OpenMW will look for a normal map called Tx_BM_snow_01_n.dds.

Parallax mapping
Parallax mapping is similar to normal mapping, except that the alpha channel contains height information. alpha = 1 -> highest, alpha = 0 -> lowest. Also, the filename postfix you need to use becomes _nh (e.g. Tx_BM_snow_01_nh.dds) so that OpenMW knows that height information is available.