Maya Blobby Displacement

When moving the blobby shape out of the surface area it is truncated. I'd like to see the blobby cause the cylinder surface to be attracted toward the new surface position.

GetMaya Scene Surface Shader Code
Get Displacement Shader Code
Get Slim Settings

Maya Scene

Slim Surface Shader Settings pnt = [mattr "nurbsCylinder1.pntD" $F]

Slim Displacment Shader Settings pntD = [mattr "nurbsCylinder1.pntD" $F]

Surface Shader Code

/*	test shader for color at point "pnt"	*/
surface
simple_blobby(float   	Kd = 1,
		iso = 0.5,
		blur = .05,
	 rad = 1;
	    point   pnt = 0;
		color	blobCol = color(0,0,1))
{



/*	variables	*/
normal   nf, n;
color    diffusecolor, surfcolor = Cs;
point    p;
float	 totalfield = 0, dist;

n = normalize(N);
nf = faceforward(n, I);
Oi = Os;
p = transform("current", pnt);
dist = distance(P, p);
totalfield += 1 - smoothstep(0, rad, dist);

    

/*

if(totalfield > iso)
    surfcolor = color(1, 0, 0);
*/

float blend = smoothstep(iso - blur, iso, totalfield);
surfcolor = mix(Cs,blobCol,blend);

diffusecolor = Kd * diffuse(nf);
Ci = Oi * Cs * surfcolor * diffusecolor;
}

Displacement Shader Code

/* Displacement blobby shader based on surface position */
displacement
blobbyDisp(float 	Km = 0.1,/*displacement magnitude*/
				
	radD = 1,	/*blobby radius	*/
					isoD = 0.5,
					blurD = .05;
			point   pntD = 0;
	)
{

normal 	n = normalize(N);
float 	totalfieldD = 0, distD;
float	hump = 0;
point 	pD;



pD = transform("current", pntD);
distD = distance(P, pD);
totalfieldD += 1 - smoothstep(0, radD, distD);

	

float blend = 1 - smoothstep(isoD - blurD, isoD, totalfieldD);
hump = mix(0, 1, blend);





/*	Calculate the surface displacement	*/
P =  P - n * hump * Km;
N = calculatenormal(P);
}