Improved normal encoding for transmissive surfs
Improved semi-auto terrain mesh blend; now independent control over distance and steepness blends, height masked, follows mesh normal, etc..
Fixed always hitting temp register issues at every corner by refactoring terrain shader code
Added proper atlas set names to override splat selection; also fixed overrides
Renamed elevation to altitude in atmosblend, for consistency
Wetness masks now optional in std shader's wet layer to free up samplers
Made terrain an optional std shader layer, now more centralized
Added useful std layers to relevant std shaders
Added directional fade to terrain-blend shader where mesh and terrain normals converge
Added speed tree asset cleanup tool "Tools/Cleanup/SpeeTree Cleanup"
Fixed testlevel terrain not showing properly
Fixed menu scene and a few other terrain mats; added back 4-layer terrain shader temporarily until menuscene gets remade
Moved horizon fade env refl occlusion into RustPBSLighting to save ALU
Traded detail spec map for occlusion map; also affects env refl occlusion
Swapped rust std shader wetness order to be after particle accum
Improved shader parity with original std shader