$pointsamplemagfilter is a material shader parameter available in Counter-Strike: Global Offensive for
LightmappedGeneric. It disables texture filtering on a material if the texture resolution is bigger than the space it occupies onscreen, and linearly interpolated (smooth) if its smaller, and will use mipmaps.
This makes it pixelated when near the texture, but smooth when far way, and will not produce moiré patterns when viewed at grazing angles or from distance, compared to just enabling Point Sampling flag in a material's VTF.
VMT syntax example