Export 3D sphere to DXF format, or any format that geometry in Comsol receive

I Have three matrixes, X, Y, and Z, that create a 3D sphere; each matrix is 100x100. I'm trying to figure out how I can export the sphere in DXF format to reload it in Comsol.

Here my code:

Thanks all

% Clear the workspace
clear
clc

% Define the dimensions of the sphere
semiMajorAxis = 1;      % Semi-major axis
semiMinorAxis = 0.5;    % Semi-minor axis (ratio of 0.9)

% Define the number of points for sphere meshing
numPoints = 100;

% Create a meshgrid for the sphere
phi = linspace(0, pi, numPoints);
theta = linspace(0, 2*pi, numPoints);
[phi, theta] = meshgrid(phi, theta);

% Calculate the coordinates of the points on the ellipsoid
x = semiMajorAxis * sin(phi) .* cos(theta);
y = semiMajorAxis * sin(phi) .* sin(theta);
z = semiMinorAxis * cos(phi);

% Define the tilt angle in radians (45 degrees upward)
tiltAngle = deg2rad(45);

% Define the rotation matrix for the tilt
R = [1, 0, 0; 0, cos(tiltAngle), -sin(tiltAngle); 0, sin(tiltAngle), cos(tiltAngle)];

% Apply the rotation matrix to the coordinates
rotatedCoords = R * [x(:)'; y(:)'; z(:)'];

% Reshape the rotated coordinates back to a grid
xRotated = reshape(rotatedCoords(1, :), size(x));
yRotated = reshape(rotatedCoords(2, :), size(y));
zRotated = reshape(rotatedCoords(3, :), size(z));

% Create a 3D plot of the tilted ellipsoid
subplot(1,2,1)
surf(xRotated, yRotated, zRotated);
axis equal;  % Equal aspect ratio

xlabel('X');
ylabel('Y');
zlabel('Z');
title('3D Sphere with Ratio 1:0.9 (45-Degree Upward Tilt)');

grid on;

Answer 1

[Akshat]

Hi @Yaad Ben Lulu

I understand that you want to export a 3D sphere to DXF format. To achieve this, you can use the 'writeDXF' function available on the MathWorks File Exchange. This function allows you to export 3D coordinates to a DXF file. You can download the 'writeDXF' function from the following link:

https://in.mathworks.com/matlabcentral/fileexchange/333-writedxf-m?s_tid=srchtitle_support_results_1_writeDXF

Once you have the 'writeDXF' function file, make sure to add it to your working folder to initiate a call to it from your script. To generate the DXF file, you can add the following line at bottom of your code.

writedxf('output', xRotated, yRotated, zRotated);

On execution, it will export the sphere coordinates to a DXF file named 'output.dxf'.

I hope this helps.

[Yaad Ben Lulu]

Thanks a lot, help my immediately