function [] = plot_teapot(data, s, t)
q = size(data);
p = q(1);
MB = [-1 3 -3 1; 3 -6 3 0; -3 3 0 0; 1 0 0 0];
%the magic bezier matrix.
%the below if's decide whether resolution information
%has been given for all the patches independently or 
%if there is just a constant resolution.
qs = size(s); qt = size(t);
if qs(2) == 1
    for i = 1:p/4
        S(i) = s;
    end
else
    S = s;
end
if qt(2) == 1
    for i = 1:p/4
        T(i) = t;
    end
else
    T = t;
end

X = [0]; Y = [0]; Z = [0];
figure, plot3(X,Y,Z,'w');
%this bit above starts the plot so we can add to it
%with the line function.

%for each patch...
for k = 1:4:p
    CX = data(k:k+3,[1 4 7 10]);
    CY = data(k:k+3,[2 5 8 11]);
    CZ = data(k:k+3,[3 6 9 12]);
    
    %clear the line segments in case the resolution 
    %has changed.
    clear('X','Y','Z');
    
    %for each s, for all t along that s, add some more
    %line.
    for i = 0:S((k+3)/4)
        for j = 1:T((k+3)/4)+1
            res = bez(CX,MB,i/S((k+3)/4),(j-1)/T((k+3)/4));
            X(j) = res(1); vs(1) = res(2); vt(1) = res(3);
            res = bez(CY,MB,i/S((k+3)/4),(j-1)/T((k+3)/4));
            Y(j) = res(1); vs(2) = res(2); vt(2) = res(3);
            res = bez(CZ,MB,i/S((k+3)/4),(j-1)/T((k+3)/4));
            Z(j) = res(1); vs(3) = res(2); vt(3) = res(3);
            cr = cross(vs,vt);
            if norm(cr) ~= 0 
                cr = cr/norm(cr);
            end
            %draws the normal.
            line([X(j) X(j)+3*cr(1)], [Y(j) Y(j)+3*cr(2)], [Z(j) Z(j)+3*cr(3)],'Color',[.1 0 1]);
        end
        %draws the line segments for this s.
        line(X,Y,Z,'Color',[0 0 0]);
    end
    
    %as above, except now for each t, for all s along that t,
    %add some more line and draw.  Notice that we need not
    %redraw the normals, since the points are the same.  In 
    %fact, with some additional data structure, this second
    %nested for loop would be unecessary.
    for j = 0:T((k+3)/4)
        for i = 1:S((k+3)/4)+1
            res = bez(CX,MB,(i-1)/S((k+3)/4),j/T((k+3)/4));
            X(i) = res(1); vs(1) = res(2); vt(1) = res(3);
            res = bez(CY,MB,(i-1)/S((k+3)/4),j/T((k+3)/4));
            Y(i) = res(1); vs(2) = res(2); vt(2) = res(3);
            res = bez(CZ,MB,(i-1)/S((k+3)/4),j/T((k+3)/4));
            Z(i) = res(1); vs(3) = res(2); vt(3) = res(3);
        end
        line(X,Y,Z,'Color',[0 0 0]);
    end
end