define freq 4
define density 0.15
define wire_exper (|fmod(freq * P[0], 1)| < density ? 1 : (|fmod(freq * P[1], 1)| < density ? 1 : 0))

define wire_red texture
{
   special surface
   {
      ambient wire_exper * red, 0.1
      diffuse wire_exper * red, 0.4
      specular wire_exper * white, 0.5
      microfacet Reitz 10
      transmission white, 1 - wire_exper, 1.0
   }
}