surface
electron_mic(
	  float Kd = 1; 
	  color coloredge = color (0.529,0.529,0.427))
{
float rim_width = .01;

normal n = normalize(N);
normal nf = faceforward(n, I, n);;

vector i = normalize(-I);
float  dot = 1 - i.nf;
Oi = smoothstep(1 - rim_width, 1.0, dot);
Oi = 1;

color diffusecolor = 1 - nf.i;

Ci = Oi * Cs * diffusecolor * coloredge * Kd;
}