displacement
wgs_fire02(
			float Km = 0.1,
            freq = 5,
            amp = 1;
            string space = "object"
)
{
float hump = 0;
point n = normalize(N);
point pp = transform(space, P);
  
hump = noise(pp * freq) * amp;
  
P = P - n * hump * Km;
N = calculatenormal(P);
}
		//notes
//http://www.fundza.com/rman_shaders/noise/index.html