surface hb_plastic(

float Ks = 0.5;

float Kd = 0.5;

float Ka = 1;

float roughness = 0.2;

color specular_color = 1;

)

{

varying color Cambient = Cs*Ka;

varying color Cdiffuse = Cs*Kd;

varying color Cspecular = specular_color*Ks;

varying float Froughness = roughness;

uniform float stream_start = hb_interact_stream();

 

varying float stream_control = 0;

varying float stream_point = hb_interact_stream("control",

gridpattern("concentric",stream_control));

stream_point += hb_interact_stream("P",transform("world",P));

stream_point += hb_interact_stream("N",normalize(ntransform("world",N)));

stream_point += hb_interact_stream("Cambient",Cambient);

stream_point += hb_interact_stream("Cdiffuse",Cdiffuse);

stream_point += hb_interact_stream("Cspecular",Cspecular);

stream_point += hb_interact_stream("Froughness",Froughness);

 

N=normalize(N);

Oi = Os;

Ci = Os*(Cambient*ambient() + Cdiffuse*diffuse(N) + Cspecular*specular(N,-normalize(I),Froughness));

}