Enhanced PBR Lighting for OpenMW, version 2.3, by Rafael (Nexus 53667).

  files in this directory   the twelve files of the "OpenMW 0.51" variant of
                            the download, CRLF normalised to LF, with the three
                            marked [SILTSTRIDER] constant changes listed below
                            - plus ONE file that is not Rafael's at all,
                            compatibility/normals.glsl, which is the stock
                            engine file with an include guard added. Its own
                            header says why it has to be here. LICENSE and
                            README.txt are the copies shipped in the download.
  licence                   GNU GPL v3 - see LICENSE beside this file. The
                            engine around it is GPLv3 as well, so redistribution
                            inside the Silt Strider client is what the licence
                            contemplates; the licence text and README.txt (the
                            credit) must keep shipping with these files.
  the other half            Rafael also publishes a post-processing pack
                            (RafaelsShaderPack, .omwfx + L10n + Textures). That
                            is a DATA DIRECTORY and rides the modpack, not this
                            tree. Nothing here depends on it being installed.
  water_nm.png              the download also carries a replacement water normal
                            map. It is a VFS texture (textures/omw/water_nm.png),
                            not a shader, so a pack directory cannot carry it;
                            NOT applied. See the 1.6 report.

The pack is not a complete shader tree. The engine searches this directory
first and falls back to resources/shaders for every file the pack does not
override (components/shader/shadermanager.cpp, resolveShaderFile). Do not
"complete" it by copying the other files in.

WHAT WE CHANGED - all three are in lib/light/lighting.glsl:

  SPECULAR_MAP_INTERPRETATION  2 -> 1
      2 reads a "_spec" texture as PBR data (R metallic, G roughness, B AO).
      Our modpack ships 3394 classic Morrowind RGB specular maps and no PBR
      parameter maps, so 2 would read gloss as roughness on every one of them.
      1 estimates safe PBR parameters from a specular map.

  FOG_DISABLED                 1 -> 0
      1 returns the colour unchanged from applyFogAtDist, i.e. no distance fog
      anywhere. The author replaces fog with the VAIO and DIVE post-processing
      effects, which this client does not guarantee.

  INTERIOR_SHADOWS_DISABLED    1 -> 0
      The pack's own comment: this constant must MATCH the in-game setting or
      interiors come out with everything in shadow. We ship
      [Shadows] enable indoor shadows = true.

WEATHER_PARTICLES_DISABLED is defined as 1 in this version and read by no file
in this tree or in stock 0.51; left as shipped.
