plotting a 3d surface on the screen of an oscilloscope

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EMMANUEL VIRATEL 2021-1-31

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链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/731968-plotting-a-3d-surface-on-the-screen-of-an-oscilloscope

Hello everyone,

I'm Emmanuel, a student from Toulouse (France). I've found this exemple on mathworks

and it works but i want to get the coordonates in a plan 2D in order to send it to the soundcard of my computer and drawing it on my oscilloscope. I want to get the most beautiful figure. I've made a script (after the original script, it use the function viewmtx), but i'm not satisfy by the result. Pleased would you help me!!!

my email: viratelemmanuel@yahoo.fr

The original script from mathworks 
theta = 0:pi/40:pi;                   % polar angle
phi = 0:pi/20:2*pi;                   % azimuth angle
[phi,theta] = meshgrid(phi,theta);    % define the grid
degree = 6;
order = 1;
amplitude = 90;
radius = 5;
Ymn = legendre(degree,cos(theta(:,1)));
Ymn = Ymn(order+1,:)';
yy = Ymn;
for kk = 2: size(theta,1)
    yy = [yy Ymn];
end
yy = yy.*cos(order*phi);
order = max(max(abs(yy)));
rho = radius + amplitude*yy/order;
r = rho.*sin(theta);    % convert to Cartesian coordinates
x = r.*cos(phi);
y = r.*sin(phi);
z = rho.*cos(theta);
figure
s = surf(x,y,z);
light               % add a light
lighting gouraud    % preferred lighting for a curved surface
% axis equal off      % set axis equal and remove axis
% view(40,-10)         % set viewpoint
camzoom(1.5)        % zoom into scene
scale = [ linspace(1,-1,40)];    % surface scaling (0 to 1 to -1)
while true 
for ii = 1:length(scale)
    rho = scale(ii)*amplitude;
%     r = rho.*sin(theta);
%     x = r.*cos(phi);
%     y = r.*sin(phi);
%     z = rho.*cos(theta);
% 
%     s.XData = x;    % replace surface x values
%     s.YData = y;    % replace surface y values
%     s.ZData = z;    % replace surface z values
    
    view(rho,rho);
    pause(0.05)     % pause to control animation speed
end
end
My script with viewmtx and a projection
   theta = 0:pi/40:pi;                   % polar angle
phi = 0:pi/20:2*pi;                   % azimuth angle
[phi,theta] = meshgrid(phi,theta);    % define the grid
degree = 6;
order = 1;
amplitude = 90;
radius = 5;
Ymn = legendre(degree,cos(theta(:,1)));
Ymn = Ymn(order+1,:)';
yy = Ymn;
for kk = 2: size(theta,1)
    yy = [yy Ymn];
end
yy = yy.*cos(order*phi);
order = max(max(abs(yy)));
rho = radius + amplitude*yy/order;
r = rho.*sin(theta);    % convert to Cartesian coordinates
x = r.*cos(phi);
y = r.*sin(phi);
z = rho.*cos(theta);
scale = [ linspace(1,-1,40)];  
for ii = 1:length(scale)
    rho = scale(ii)*amplitude;
%A = viewmtx(-37.5,30);
A = viewmtx(rho,rho);
r=x(23,:);
b=y(20,:);
c=z(20,:);
m=41;
n=1;
x4d = [r;b;c;ones(n,m )];
x2d = A*x4d;
x2 = zeros(m,n); y2 = zeros(m,n);
x2(:) = x2d(1,:);
y2(:) = x2d(2,:);
 plot(x2,y2);
% ones(m*n,1)
%   plot(y(:,t),z(:,t));
  
  pause (0.5)
  
end