x_padding = 1;
y_padding = 1;
yaw = -3:x_padding:3;
pitch = -3:y_padding:3;
% yaw 是水平转动
% pitch 是上下俯仰
sig=1.5;
[X,Y ]= meshgrid(yaw,pitch);
Z = X.^2 + Y.^2;
% Z=exp(-(X.^2+Y.^2)./sig.^2);
[gx,gy] = gradient(Z,x_padding,y_padding);
figure
% mesh(Z)
hold on;
for y = 1:length(yaw)
    for p = 1:length(pitch)
        s = [yaw(y) pitch(p) Z(y,p)];
        n = [gx(y,p) gy(y,p) -1+rand()*0.1];
        n = n/norm(n);
        e = s+n;
        quiver3(s(1),s(2),s(3),e(1),e(2),e(3),'r');
        hold on;
    end 
end
axis equal