displacement
lowell_dis(uniform float         Km   = 0.1
						       /*freq = 1*/;
		 string texname = "H:/vsfx727/textures/lowellOregon.tx";
		 output varying float  hump = 0)
{

normal n = normalize(N);
if(texname != "")
hump = texture(texname);


P = P - n * hump * Km;
N = calculatenormal(P);
}