#define INNER	0.00

displacement
ovalnoised( float
		Ad = 0.10,  // u diameter
		Bd = 0.10,  // v diameter
		NoiseAmp = 0.00,	// noise amplitude
		DispAmp = 0.10		// displacement amplitude
)
{
	float Ar = Ad / 2.;	// u radius
	float Br = Bd / 2.;	// v radius

	point PP = point "shader" P;

	float magnitude = 0.;
	float size = 1.;
	float i;
	for( i = 0.; i < 6.0; i += 1.0 )
	{
		magnitude += ( .5 - noise( size * PP ) ) / size;
		size *= 2.0;
	}

	float up = 2. * u;
	float vp = v;


	float numinu = floor( up / Ad );
	float numinv = floor( vp / Bd );

	up = up - numinu * Ad;
	vp = vp - numinv * Bd;
	point upvp =  point( up, vp, 0. );
	point cntr =  point( Ar, Br, 0. );
	vector delta = upvp - cntr;
	float oldrad = length( delta );
	float newrad = oldrad + NoiseAmp*magnitude;
	delta = delta * newrad / oldrad;
	float du = xcomp(delta)/Ar;
	float dv = ycomp(delta)/Br;
	float d = du*du + dv*dv;
	float disp = DispAmp * ( 1. - d );
	disp = disp * ( 1. - smoothstep( INNER, 1.,  d ) );

	if( disp != 0. )
	{
		P = P + normalize(N) * disp;
		N = calculatenormal(P);
	}
	// N = calculatenormal( P + normalize(N) * disp );
}