3D plotting in MATLAB

I have 3 sensors wich are situated in X Y Z axes.

From those sensors , I have a data which is a 3D matrix. The question is :

a) Need to plot the position data(3D matrix) as circles using plot3

b) Also Need to plot a 1cm long line into both directions along the sensor's orientation.

% My probable Solution for First Part

sensor_data = randi([1 10],16,16,16); %
figure;
subplot(1,2,1);
plot3(xt,yt,zt,'o');
grid on

%  My probable Solution for Second Part

subplot(1,2,2);
plot3(xt, yt, zt, 'LineWidth',1);
grid on

I am confused with the second portion specifically : "Need to plot a 1cm long line into both directions" .

Are my solutions correct ? or what might be the probable solution for second part.