How can I rotate the following cube in real time?

Hello to everyone,

I´m reading some data of an IMU in a microcontroller and I send "roll, pitch and "yaw" information from the angles to Matlab by serial port. I have created that multicolor cube in order to know better which part of the sensor is each face of the cube. I would like to create a function that receives roll, pitch and yaw angle values and then rotates the cube in real time.

patch([0, 4, 4, 0], [0, 0, 3, 3], [0, 0, 0, 0], 'blue') %Cara de la parte de abajo de la imu
patch([0, 4, 4, 0], [0, 0, 3, 3], [1, 1, 1, 1], 'red') %Cara de la parte de arriba
patch([0, 0, 0, 0], [0, 0, 3, 3], [0, 1, 1, 0], 'green') %Borde corto nº1 del sensor
patch([0, 4, 4, 0], [0, 0, 0, 0], [0, 0, 1, 1], 'yellow') %Borde largo nº1 del sensor
patch([4, 4, 4, 4], [0, 3, 3, 0], [0, 0, 1, 1], 'magenta') %Borde largo nº2 del sensor
patch([4, 4, 0, 0], [3, 3, 3, 3], [0, 1, 1, 0], 'cyan') %Borde corto nº2 del sensor

axis square

Thank you in advance,

Answer 1

[KSSV]

X = [0, 4, 4, 0
    0, 4, 4, 0
    0, 0, 0, 0
    0, 4, 4, 0
    4, 4, 4, 4
    4, 4, 0, 0] ;
Y = [0, 0, 3, 3
    0, 0, 3, 3
    0, 0, 3, 3
    0, 0, 0, 0
    0, 3, 3, 0
    3, 3, 3, 3] ;
Z = [0, 0, 0, 0
    1, 1, 1, 1
    0, 1, 1, 0
    0, 0, 1, 1
    0, 0, 1, 1
    0, 1, 1, 0] ;
C = {'blue' ;'red' ; 'green' ; 'yellow' ; 'magenta' ; 'cyan'};

figure
hold on
for i = 1:6
    patch(X(i,:), Y(i,:), Z(i,:),C{i}) ;
end
axis square
view(3)
%% Rotate
th = linspace(0,2*pi) ;
for i = 1:length(th)
    R = [1 0 0 ;0 cos(th(i)) -sin(th(i)) ; 0 sin(th(i)) cos(th(i))] ;
    T = [X(:) Y(:) Z(:)]*R ;
    Xi = reshape(T(:,1),[],4) ;
    Yi = reshape(T(:,2),[],4) ;
    Zi = reshape(T(:,3),[],4) ;
    figure(1)
    hold on
    for j = 1:6
        patch(Xi(j,:), Yi(j,:), Zi(j,:),C{j}) ;
    end
    axis square
    view(3)
    drawnow
    hold off
    clf
    
end

Can be improved a lot.

[Aitor Burdaspar]

Thank you very much for answering so quickly. Anyway, it doesn´t respond fine to the signal I send from the serial port. I have done this main program which reads the data from the serial port:

% I initialize the serial port where I will work. I delete previous data and declare the port and data transfer speed
delete(instrfind({'Port'}, {'COM3'}));
arduino = serial('COM3');
arduino.Baudrate = 9600;
fopen(arduino); %Open serial port
warning('off','MATLAB:serial:fscanf:unsuccesfulRead');

figure('Name', 'Serial communication: MATLAB + Arduino = CUBE 3D');
hold on
while 1
x = fscanf(arduino, '%f');
y = fscanf(arduino, '%f');
z = fscanf(arduino, '%f');
plotCube3Angles_2(x, y, z) %Function in order to rotate
drawnow limitrate %Create a 3d figure and plot in real time
clf %Clean figure and update it
end

Then, the "plotCube3Angles_2(x, y, z)" function is the following one:

function plotCube3Angles_2(roll, pitch, yaw)
 %I define the vertex of the rectangle
 vertex_matrix = [0 0 0
4 0 0
4 3 0
0 3 0
0 0 1
4 0 1
4 3 1
0 3 1];
 %I define the faces of the rectangle
faces_matrix = [1 2 6 5
2 3 7 6
3 4 8 7
4 1 5 8
1 2 3 4
5 6 7 8];
 
subplot(1,3,1)
axis([0 4 0 3 0 1]); %axis limits
axis equal off; %serves to prevent Matlab from distorting the image to fit the window
cube = patch('Vertices',vertex_matrix,'Faces',faces_matrix,'FaceColor', 'blue'); %Create a 3d blue rectangle of the previous characteristics
rotate(cube, [1,0,0], roll); %rotate => 'object', 'rotation direction (of axis)', 'numeric value for rotation'
rotate(cube,[0,1,0], pitch);
rotate(cube, [0, 0, 1], yaw);
view(0,0); %view (0,0) places the camera completely horizontal so as not to disturb the perspective
 
end

In this way, it works fine. But, as you can see, in the way I create the rectangle, I can only choose the colour for the entire object. I would like to give different colours for each face.

It might be a silly thing, but I've tried it in different ways and I have not got it.

I would be grateful if someone answered me.