Whether to try and replace error textures with more meaningful ones for gameplay (see also mat_error_texture_advanced_basetexture).

mat_error_texture_advanced 0
0: Off, default error texture

mat_error_texture_advanced 1
1: Base color based on VRAD reflectivity data applied to texture specified in mat_error_texture_advanced_basetexture

mat_error_texture_advanced 2
2: Same as 1 but also replace water, grates and glass with meaningful textures