Several surface flags are available in Quetoo that were not previously supported by Quake 2.
SURF_NO_DRAW
Comparable to Quake III Arena's caulk feature; disables rendering of any face to which it is applied. Useful on backs of beams, bottoms of crates, etc.. The BSP compiler automatically assigns this flag to any surfaces textured with common/caulk.
SURF_TRANS33 + SURF_TRANS66
Combining the two legacy alpha blend flags causes the renderer to use the texture's alpha channel for blending. This is useful for light volumes and decals.
SURF_ALPHATEST
Enables OpenGL alpha-test on surfaces to which it is applied, allowing for grates, foliage, railings, fences, and other textures with "holes".
SURF_PHONG
Marks surfaces for Phong Interpolation (Phong Shading) during the BSP compile process. This should only be used on curved or organic geometry such as pipes, pillars, and terrain.
