message: Add comment explaining an odd choice
diff: // Material parameters
  //------------------------------------------------------------------------------
  +// These variables should be in a struct but some GPU drivers ignore the
  +// precision qualifier on individual struct members
  HIGHP mat3 shading_tangentToWorld; // TBN matrix
  HIGHP vec3 shading_position; // position of the fragment in world space
  vec3 shading_view; // normalized vector from the fragment to the eye
  