Initial work on foliage perf optimizations - Alpha culling by clipping before we even get to the PS Make specular optional Fustrum cull triangles Experiment with culling during shadow pass for foliage Added transmission Swap branch materials to new shader Fix AMD specular issue Make trees more filled out Introduced culled_depth variant Merge pull request #141 from Facepunch/foliage-perf Foliage performance improvements