for a = 0:pi/50:2*pi
t = linspace(0,a);
r = linspace(0,3);
[T,R]=meshgrid(t,r);
X = R.*cos(T);
Y = R.*sin(T);
Z = sqrt(9-R.^2);
subplot(2,3,5)
surf(X,Y,Z, 'facealpha', 0.95)
shading interp
camlight right
lighting phong
material shiny
axis equal
pause(0.01)
end