As far as i tested it, NormalMapFilter affects EnvironmentFilter, but does not affect the PlanarFilter, although it is very desirable to show some reflecting effects with normal map on plane. I know, that it is possible to write my own FLSL, but is it possible to use the language for my task? If yes, how would the code look? Or could you, fior instance, show the source of EnvironmentFilter, so I could use it as a start point for my PlanarNormalMap FLSL script?