/* Shader description goes here */
surface
blobby3(float	Kd = 1,
				iso = 0.5;
		float	rad[3] = { 1, 1, 1 };
		point	pnt[3] = { 0, 0, 0 };
		color	col[3] = { 1, 1, 1 };
		
		 )
{
normal	nf, n;
color	diffusecolor,
		surfcolor = 1, surfopac = Os;
point	p;

/* STEP 1 - make a copy of the surface normal one unit in length */
n = normalize(N);
nf = faceforward(n, I);

/* STEP 2 - set the apparent surface opacity */
Oi = surfopac;

float 	totalfield = 0, field, dist;
color	totalcolor = 0;
uniform float j;
for(j = 0; j < 3; j = j + 1)
	{
	dist = distance(pnt[j], p);
	field = 1 - smoothstep(0, rad[j], dist);
	totalcolor += col[j] * field;
	totalfield += field;
	}
float r = comp(totalcolor, 0);
float g = comp(totalcolor, 1);
float b = comp(totalcolor, 2);
r /= 3;
g /= 3;
b /= 3;
setcomp(totalcolor, 0, (r > 1) ? 1 : r);
setcomp(totalcolor, 1, (g > 1) ? 1 : g);
setcomp(totalcolor, 2, (b > 1) ? 1 : b);

float blend = smoothstep(iso - 0.05, iso + 0.05, totalfield);
surfcolor = mix(Cs, totalcolor, blend);
		
/* STEP 3 - calculate the diffuse lighting component */
diffusecolor = Kd * diffuse(nf);

/* STEP 4 - calculate the apparent surface color */
Ci = Oi * Cs * surfcolor * diffusecolor;
}