frac(x)=x-floor(x);

hermite(p0,p1,r0,r1,t) =	p0 * ((2*t-3)*t*t+1) +
				p1 * (-2*t+3)*t*t +
				r0 * (((t-2)*t+1)*t) +
				r1 * ((t-1)*t*t);

rand3a(x,y,z) = 1-2*rand(.69692*x+.35084*y+.26765*z);
rand3b(x,y,z) = 1-2*rand(.05393*x+.96196*y+.28617*z);
rand3c(x,y,z) = 1-2*rand(.04234*x+.46180*y+.54550*z);
rand3d(x,y,z) = 1-2*rand(.07211*x+.76411*y+.95567*z);

noise3(x,y,z) = noise_3(	floor(x),frac(x),ceil(x),
				floor(y),frac(y),ceil(y),
				floor(z),frac(z),ceil(z) );

noise_3(xl,xd,xu,yl,yd,yu,zl,zd,zu) =
		hermite(
			hermite(
				hermite(rand3d(xl,yl,zl),
					rand3d(xu,yl,zl),
					rand3a(xl,yl,zl),
					rand3a(xu,yl,zl),
					xd),
				hermite(rand3d(xl,yu,zl),
					rand3d(xu,yu,zl),
					rand3a(xl,yu,zl),
					rand3a(xu,yu,zl),
					xd),
				(1-xd)*rand3b(xl,yl,zl)+
					xd*rand3b(xu,yl,zl),
				(1-xd)*rand3b(xl,yu,zl)+
					xd*rand3b(xu,yu,zl),
				yd),
			hermite(
				hermite(rand3d(xl,yl,zu),
					rand3d(xu,yl,zu),
					rand3a(xl,yl,zu),
					rand3a(xu,yl,zu),
					xd),
				hermite(rand3d(xl,yu,zu),
					rand3d(xu,yu,zu),
					rand3a(xl,yu,zu),
					rand3a(xu,yu,zu),
					xd),
				(1-xd)*rand3b(xl,yl,zu)+
					xd*rand3b(xu,yl,zu),
				(1-xd)*rand3b(xl,yu,zu)+
					xd*rand3b(xu,yu,zu),
				yd),
			(1-yd)*((1-xd)*rand3c(xl,yl,zl) +
					xd*rand3c(xu,yl,zl)) +
				yd*((1-xd)*rand3c(xl,yu,zl) +
					xd*rand3c(xu,yu,zl)),
			(1-yd)*((1-xd)*rand3c(xl,yl,zu) +
					xd*rand3c(xu,yl,zu)) +
				yd*((1-xd)*rand3c(xl,yu,zu) +
					xd*rand3c(xu,yu,zu)),
			zd);