// Glass textures contributed by Norm Bowler, of Richland WA
#declare NBglass =
texture {
    pigment { rgbf <0.98, 1.0, 0.99, 0.75> }
    finish {
        ambient 0.1
        diffuse 0.1
        reflection .25
        specular 1
        roughness .001
 #if (version<3.1)
    ior 1.5
 #end
    }
}

#declare Glass_Interior = interior {ior 1.5}

#declare M_NB_Glass = material {texture {NBglass} interior {Glass_Interior}}